When a repair goes bad...

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Here's a little project that's gone from a topic that could have featured in the Mechanic's Park but has gone pear shaped and then could have visited the Welding Questions forum but it has now become a Welding Project with Pictures.This is what the repair is on. Clark Michigan 85IIIALeaky water pump. See the pulley is sloped down a bit,The best part of a day later, the pump is off the Leyland. Working off a step ladder and reaching over to the motor is funThe front bearing was jiggered, the rear bearing was totally collapsed and stuck three inches in.I soaked it with penetrant and heated it and tried drifting it out. Unfortunately I had the drift against the edge and a piece broke off. The inner diameter of the race was the same as the bore of the pump body, so I couldn't get anything to press it out.Next post please."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375
Reply:I'd wondered about putting a bead of weld on the inner race to shrink it but as it was a bit far in and I was worried about getting the arc on things I didn't want arced, I tried the drift trick with disastrous results.It would have been easier to clean up stray arc spots than fix this.Great mix on this machine all the motor bolts so far have been BSF and the frame bolts are UNC and the rusty ones can be anything even BFH Metric. Whatever fits and as the rust changes the size sometimes I used the impact socket with a hammer impacting the socket onto the bolt head. Only one has been chiselled off so far. I'll put them back with Neverseize, I wish the last guy had. It's spent the last few years of it's like loading ferttiliser, so that's really good, about the opposite of Neverseize.I managed to get a bead of sorts in there with a stainless rod 10g and 110amps.Both please and annoyed that when it shrunk, it was only finger tight. Wish I'd done this before trying the drift.It's fairly thin, about 3/32nd of an inch, with a web at the front.It had to be in three bits didn't it!Only coin thick and you can see the flecks of bronze from the impeller rubbing on it when the bearings failed.So, anyone got any advice, please?My first thoughts are to braze it but I haven't done any cast repairs since the 80s and I wonder what's changed in between times.I remember some horror cases of brazing up end bells from electric motors and then listening to them crack around the bearing mount in the centre. Still we got better results in those days from brazing than we did with cast iron arc rods.I'd like this thing to go again soon and the water pumps and parts are like rocking horse droppings and so far I've found more hens teeth than I have pump castings.I don't even know which motor type it is. Anyone know how to identify Leyland 6 cyl cross flow diesels, please? I've had all sorts of experts say what they think it is, but so far nothing lines up.If braze is still the way to go, has the flux changed or do you still use a special "tinning" flux (looks like cocoa or chocolate powder) and then use the borax based flux for the filling braze?Maybe Denrep Casting Rehabilitation LLC will pass by or Castweld. All advice is welcome.I have OA and DC Tig and arc."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375
Reply:" has gone pear shaped "        The multiple small broken cast pieces sure do complicate things, eh?IIRC, castweld did a repair on an oil pan by replacing a buggered section with a replacement single piece of mild steel and then bronze brazing that patch piece into the original piece.  Darn nice repair when all was done.I don't know if you can go that route with a thin mild steel replacement patch brazed into the cast iron housing, especially since you would have to get -into- the impeller cavity area and clean up the filler line.  Castweld had access to both sides of the oil pan so he could dress everything up all neat and tidy.Maybe you could weld the small pieces back together with some nickel filler, clean it up, and then bronze braze the piece back into the main part of the housing.  You'd still have to get into the impeller cavity and clean up the inside.Hmmm, maybe just cut out the entire mounting face on the water pump and replace that whole section with a mild steel replacement patch?  Circular patch and maybe that would get the repair seam/joint out into the periphery where the impeller tips don't really reach and thus make it so you don't have to get inside the impeller cavity to clean up the seam/joint as critical?Wait a minute.  The impeller is 'outside' that housing or inside where that rusty cavity is by the bearings?Interesting to see how this all plays out.  The best laid schemes ... Gang oft agley ...
Reply:Hmmmm, considering you're in 'New Zealand', I'm sure you'd get a few 'takers' from the US or Canada, especially in the Winter!  :PI'm pretty sure that you can do BOTH, but either way, you're probably best to 'cut a new piece' for the fit-up.  Brazing those pieces together would be...'challenging' and that stuff is so brittle to begin with...If brazing, I normally scrape off about 95% of the flux that's on the rod and then mix it with abit of borax cone.  I then use the 'lightly coated' rod and dip the hot-end into the borax/flux mixture as more Bronze is needed.  For me, this works MUCH better than using the rods 'As-Is'.For TIG, I would actually consider 'ALUMINUM BRONZE' rod.  I haven't had the 'chance' to try it yet, but from what I know, it's VERY MUCH like TIG'ing with Sil-Bronze (which you could also use) and it Wets Nicely, Builds up well and has less shrinkage than any 'NICKEL ROD' (what you likely used in days gone by..).  Unfortunately, I Can't help you any with the 'engine stuff'.Cheers,/Jman..Edit:  Also, I'd clean that area up real nice and get rid of any 'penetrant' and other cleaner that you may have used.  Once you start TIG'ing and/or Flameing that area, you'll risk the chance of creating some 'Nasty Gas'.  Likely won't kill you, but would no doubt make you pretty sick.Last edited by jman; 09-02-2010 at 11:36 AM.Miller Diversion 165120 amp Buzz BoxVictor Oxy/Ace Oxy/LPGSmith "Little" Oxy/LPGHypertherm Powermax 30Lot's of Misc. tools n' crap....
Reply:With Plan A I thought to toss the small broken pieces and fab a small filler piece from plate. Bevel and braze.However, the repair would have to be very flat and close fitting to the impeller, there would be no room to spare for build-up. Which brings us to plan BWith Plan B I would fit an oversize patch to the back of the break, from inside the pump cavity, and then braze with a flow that would bond the patch from underneath and then build up to height that would be machined (filed) to match the existing flat surface. However, either repair carries some risk of cracking, and would have to be finished very flat and close fitting to the impeller. There would be no room to spare for build-up. Which brings us to plan C.With Plan C, my thought is to fabricate a thin spacer plate which would be sandwiched between the block and pump. On assembly the impeller would be pressed short of the original location. The pump would be located further away from the block by the spacer's thickness, but that shouldn't be an issue.If this were a larger or more critical pump application, I suppose there would be some possibility of the missing broken piece causing pump turbulence or bypass. In that case a filler piece could be added to the plate to nest into a cut out at the  fracture. However I don't believe the missing piece  would be an issue with this application.So... My vote is to start by placing the pump on flat plate to transfer punch the hole locations and then drill away.But still... if a reasonably priced rebuilt pump is available, that's the way to go.Good LuckLast edited by denrep; 09-02-2010 at 12:38 PM.
Reply:how about you mill out a little bit back from the crack then braze a dutchman in place and mill it down to height. That way you end up with some support onto the thicker portion of the piece and that should allow for a little bit stronger repair.  Obviously since you're working with a cast piece; pre-heat, braze, controlled cooling, etc...--Wintermute"No man's knowledge here can go beyond his experience." - John Lockewww.improvised-engineering.comManufacturer Agnostic:Blood----------Sweat---------Tears----|------------------|----------------|----Lincoln Red, Miller Blue, Esab Yellow
Reply:Can you mill 3/32" off the whole back of the pump so the lip is gone and then just put a flat plate on with a gasket?  No brazing or welding involved.My name's not Jim....
Reply:boost, that's the best method of repairing that I've heard so far...makes me feel kinda dumb that I didn't think of it.  Just mill the whole back off of the pump and replace it with a plate.  That way you can be sure of the correct clearance, no welding or brazing and you can ensure a clean flat surface made out of a stronger material than the original cast.  Should be a good quick and effective repair.  That's a good recommendation.--Wintermute"No man's knowledge here can go beyond his experience." - John Lockewww.improvised-engineering.comManufacturer Agnostic:Blood----------Sweat---------Tears----|------------------|----------------|----Lincoln Red, Miller Blue, Esab Yellow
Reply:To me, it doesn't look like there will be enough "meat" left at the edge's sealing surface if the housing is milled that far.
Reply:Originally Posted by denrepTo me, it doesn't look like there will be enough "meat" left at the edge's sealing surface if the housing is milled that far.
Reply:Thanks for all the input guys.It was late and getting later when I posted and just before I headed of for some shut eye, I thought " I really should have said that the face is conical" I don't have the impeller back yet, as i sent it off to a seal crowd. This is a radial finned impeller and the fins taper as they get further from the shaft.It's the clearance between those fins and the housing face that will determine the efficiency of the pump. The fins are on the pulley side of the impeller, unlike most auto water pumps I've seen.I'll post a picture later as hopefully the shaft and impeller will be back in a couple of hours.My first inclination had been to look at brazing the three parts back in there. The suggestion of putting in a whole new part would be easier though. I'm sure I could beat a new piece of 1/8" sheet or similar to a suitable form and then braze than in. I don't know that the efficiency is much of a concern as the impeller has beaten itself about on the housing and made the fins or blades shallower anyway. It's fed from about or just below half way down the radiator, so should have good water supply and the centrifugal action of the impeller should assist its passage through the block and head. There are heaps of parts for Leyland water pumps from Indian (sub-continent) manufacturers but as I can't establish what the engine is I can't progress in that direction.I'll post more pics later."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375
Reply:I'll go by and weld that up for you, I wish! Lots of good suggestions above, if it were in my shop I would die grind into a shape with rounded corners and cut like patch from mild steel thicker in cross section. Bevel edges and use spacer under to keep in position that leaves bottom roughly level with existing casting. This will leave patch proud or protruding. Machine to fit. Oh and i forgot- oa braze it. Heat casting untill 7 or 800 degrees (soak at this temp for 30 mins before welding)  Low fuming bronze works well for this. I have used the white flux coated and the bare with Peterson #2 high heat flux. both did good job, but high heat flux is a mess to deal with after it cools.  Keep at temp while welding, post heat at temp for 30 mins after welding and cool no more than 100 degrees per half hr down to 400 then turn off heat , cover and let cool.This is an example of a repair that will crack if heat procedure is not followed. Thin section in middle of thick. Outside or edge would be easier and you can "fudge" on pre/post heats.Do you have a oven? loose fire brick, a weed torch, and a ir thermometer works if you don't have access to oven.My 2 cents,PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:The impeller came back.Thanks for the replies, I've got a bit more to look into at the moment but the more I think about, brazing a new piece in looks like the best option so far.Can't get any Tinning flux locally, so it'll be here tomorrow (Saturday), hopefully.Note the wear on the tops and ends of the vanes."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375
Reply:I seriously considered boring the damaged section out in the lathe and then making a replacement, turned to the same angle. I was concerned about how to retain it but there's a bit of "meat" in parts of the main body that would allow that. However, the hose spigot sticks out too far and I can't swing it in the lathe.So, currently brazing still looks like the best option. I'll have to see what arrives in the way of tinning flux in the morning. I've ordered from two places, in the hope of covering all bases."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375
Reply:Originally Posted by castweldI'll go by and weld that up for you, I wish! Lots of good suggestions above, if it were in my shop I would die grind into a shape with rounded corners and cut like patch from mild steel thicker in cross section. Bevel edges and use spacer under to keep in position that leaves bottom roughly level with existing casting. This will leave patch proud or protruding. Machine to fit. Oh and i forgot- oa braze it. Heat casting untill 7 or 800 degrees (soak at this temp for 30 mins before welding)  Low fuming bronze works well for this. I have used the white flux coated and the bare with Peterson #2 high heat flux. both did good job, but high heat flux is a mess to deal with after it cools.  Keep at temp while welding, post heat at temp for 30 mins after welding and cool no more than 100 degrees per half hr down to 400 then turn off heat , cover and let cool.This is an example of a repair that will crack if heat procedure is not followed. Thin section in middle of thick. Outside or edge would be easier and you can "fudge" on pre/post heats.Do you have a oven? loose fire brick, a weed torch, and a ir thermometer works if you don't have access to oven.My 2 cents,Peter
Reply:Tractapac,"Weed burner" is pretty much same idea as what you showed, only puts out more heat than that little one.More as in approximately 500K Btu/hr.  Which is enough to frost over and darn near freeze those little 1 lb propane cylinders.  Or a 20 lb (hmm 10 kilo in metric, eh?    ) 'BBQ' propane tank/cylinder.  Yes, I have frosted/froze both sizes.Like this thing:http://www.harborfreight.com/lawn-ga...rch-91033.htmlIt is pretty much just squirting tank-pressure propane out of the tank and into the burner tube.  Sounds like a rocket engine when you squeeze the trigger and go "full throttle" .     castweld is saying to make  a small 'pit' with the firebrick to contain the object, the flame(s), and the heat instead of just waving a flame over the object.  And keep the cast iron at the heated temp for 30 minutes to make sure the heat is nicely throughout the cast iron and theat it has all had a chance to heat up nicely.  Because like he said, cast iron and thick and thin sections and extreme temperature differentials (welding or brazing) is -not- a good thing.  Unless you really want to hear that "Ting!" of cracking cast iron.   re: lime  Dry hot sand can work too.  You just want an insulator that can help keep the object at temperature and let it -slowly- cool down.  Slowly as in ~100F per hour. Slow is good, in this case.    From the 'hot' to the 'cold' is like completely overnight.  The best laid schemes ... Gang oft agley ...
Reply:really good insulators for cheap:Perlite, Vermiculite, and wood ashesMillerMatic 252, HTP 221 w/cooler, Hypertherm PM45, Lincoln IdealArc 250 AC/DC"I'd like to believe as many true things and as few false things as possible"
Reply:really good insulators for cheap:Perlite, Vermiculite, and wood ashes
Reply:Originally Posted by MoonRiseTractapac,"Weed burner" is pretty much same idea as what you showed, only puts out more heat than that little one.More as in approximately 500K Btu/hr.  Which is enough to frost over and darn near freeze those little 1 lb propane cylinders.  Or a 20 lb (hmm 10 kilo in metric, eh?    ) 'BBQ' propane tank/cylinder.  Yes, I have frosted/froze both sizes.Like this thing:http://www.harborfreight.com/lawn-ga...rch-91033.htmlIt is pretty much just squirting tank-pressure propane out of the tank and into the burner tube.  Sounds like a rocket engine when you squeeze the trigger and go "full throttle" .     castweld is saying to make  a small 'pit' with the firebrick to contain the object, the flame(s), and the heat instead of just waving a flame over the object.  And keep the cast iron at the heated temp for 30 minutes to make sure the heat is nicely throughout the cast iron and theat it has all had a chance to heat up nicely.  Because like he said, cast iron and thick and thin sections and extreme temperature differentials (welding or brazing) is -not- a good thing.  Unless you really want to hear that "Ting!" of cracking cast iron.   re: lime  Dry hot sand can work too.  You just want an insulator that can help keep the object at temperature and let it -slowly- cool down.  Slowly as in ~100F per hour. Slow is good, in this case.    From the 'hot' to the 'cold' is like completely overnight.
Reply:Originally Posted by Tractapac#1 - Check these out:http://www.trademe.co.nz/Home-living...-314987544.htmhttp://www.trademe.co.nz/Sports/Hunt...-314239388.htm#2 - Is Floor Dry like the kitty litter or the oil, absorber?
Reply:I might have to make one, I see in old posts there's samples from Denrep of a Weed Burner and Castweld's furnace using mig tips for jets.I'm a bit delayed as it dawned on me that I'd been planning this on the basis that I used to do it with full sized OA bottles but when reality arrived and I now only have Handyman sized bottles. I realised that the OA will have to be saved for the braze and heating will be LPG (propane). I have to check out someone who may have an oven next week. But it'd be more convenient to do it at our place, rather than someone else's shop.Yep, 9kg is the BBQ bottle here and I do have a 45kg cylinder as well, 100 pound.I degreased around the engine today but still haven't found an engine number. I did find the diesel tank level sender though, under a tread plate with moss and grass growing over it. There's a 5/8" gap to the top of the tank and it was chocker with sand stones and fertiliser and took a lot of cleaning to get it all out.Is Floor Dry like the kitty litter or the oil, absorber?[/QUOTE]I can get better pics and some suggestions to build a propane burner, one should be enough. (a lot cheaper than those) Can give ideas how to use loose brick for oven, a very large casting repair shop here in Louisiana did not use dedicated ovens but temporary brick enclosure for welding. Fire brick once heated cools slowly enough that on most jobs simply turning off burner and closing burner hole will give adequate cooling period. Using brick would eliminate having to use lime, vermiculite, oil dry, perlite, or wood ash. Those would work but biggest concern is getting fron 750 degrees to 400. Once casting hits 400 just keeping it out of a breeze, and let it cool will work.PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Originally Posted by castweldI might have to make one, I see in old posts there's samples from Denrep of a Weed Burner and Castweld's furnace using mig tips for jets.I degreased around the engine today but still haven't found an engine number. I did find the diesel tank level sender though, under a tread plate with moss and grass growing over it. There's a 5/8" gap to the top of the tank and it was chocker with sand stones and fertiliser and took a lot of cleaning to get it all out.Is Floor Dry like the kitty litter or the oil, absorber?
Reply:SimonYou may want to look at Matt's post in mig,tig, stick. Old welding publication. Around page fifty-something it explains a brick oven. Lots of stuff that you can use on your project.PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Thanks for that. Magic book! Safely stashed away in "Documents" now."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375
Reply:I've had this welding bench for a while. Bought it in an online auction and went to collect it. Quite a bit of fun to extract it from someone's shed behind their house, jack knife the trailer after getting it down a drive, then unhook it and push it further round by hand. Armed with a bottle jack and chainblock and chains, it took about three hours to load. Fortuately we could tow it out easier than when we got the trailer in. First stop gas station and 60psi in the tyres.Anyway, long story short, it has a good supply of fire bricks, or refractory bricks. It turns out that the brick section goes quite a way under the top level. So I though if we got a couple of bricks loose we'd have plenty of bricks available to make a temporary brazing pit.Haven't got room for it inside, so we put a roof on it, in a manner of speaking.The bricks go all the way forward, to the middle leg, on the lower level.Wee bit of carnage getting them loose. Thought I'd have to break one to get them loose but there was a bit of collateral damage.Our $1 coin is about 7/8" in diameter. Years of rust build up. It must have been a big brick topped table with a small raised area and then as times changed, the top area was expanded, covering the bricks. No wonder it was heavy.Looking in under the top area. Note the chipped corner on the next row of bricks. Caused by the tightness created by the expansion of rust both underneath and on the sides of the frame.More in the next post."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375In getting the bricks out, I kept coming across these pieces of lead that were in between the bricks. I doubt they were put there intentionally but they'd be a good way to "tighten" up the bricks in the table top.I think if I was to make this sort of table, after taking these bricks out, I'd build a table where the bricks fitted against the frame on two adjoining sides and were retained with a bar on the opposite sides tensioned by bolts or wedges. Then when you released the two mechanically fastened sides, the bricks would be unrestrained for removal. But I guess when you make a table like this, firstly it would probably be under cover and have less corrosion and secondly it'd be years before you had to think about replacing bricks.They moulded in and around the ends of some bricks, really locking them together. Rust never sleeps (Neil Young) this bit was 3/8" thick.Brazing pit under way. I'll maybe place a piece of gib board or two(sorry you call it drywall I think) on the top and then weight that with more bricks or bits thereof.I was trying to find some firebricks locally and the closest crowd that has them is about 40 miles away. So, after I'd left them a message a couple of days ago and then pulled all the bricks out, I got a reply and recommending some Insulation bricks, which are evidently easier to cut and insulate better. They won't freight small numbers because of freight costs and damage, so I may have to visit them to collect them.I collected an LPG (propane) torch today, the type they shrink wrap pallets with. Not quite the 500K BTUs but pretty grunty none the less."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375
Reply:Waiting to see how this all turns out.Ixnay (aka NO ) on using drywall/gib board for the top layer of your furnace/oven.  Once the paper burns on the dry wall, the 'chalk' (gypsum) filling has no real strength.  The gypsum won't really burn, but once the paper does the bricks on top will just crash right through.  Just creatively stack more firebricks on the top to close off the furnace/oven.Yeah, rust -never- sleeps.Speaking of which, you probably would NOT want to mechanically lock the firebricks into place in a steel structure because of thermal expansion.  The best laid schemes ... Gang oft agley ...
Reply:Small burner small tube=1 1/4 od x 1 id x 3.2" long flame holder= 1 1/2 od x 1 1/4 id x 1.2 long mig tip for .035 wire, end of tip .350 into small tubefirst flame pic at 2psi, second at 40psi. flame unstablem at 40! I usually run in 5-10psi range.Big burner 2.8 id tube x 9 3/8  jet is 1/8 pipe thread grease zerk, guts out.This is my crawfish boiling rig that is over 10 years old. I don't use pressure regulator, just tank valve. This will freeze a small tank quickly if run wide open. Would need 200+ gal tank to run without freezing. I don't let anyone borrow this one, have to use common sense when playing with that much fire.Simon I don't think you need one this size for that water pump!! Attached ImagesEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:more pics Attached ImagesEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:last one Attached ImagesEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Houston, We have ignition and are go for launch! The only problem is you've got your rocket upside down!.No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:SimonI was looking at your brick oven, I'd suggest putting a steel plate smaller than the inside of oven ontop of bricks. Put bricks ontop of plate then casting on bricks. Remove 1 brick from outside wall that in under plate for burner. This will give casting much more even heating. A sheet metal top to cover opening and give welding access. Be sure to dry bricks before use. If bricks havn't been used recently they have moisture in them. "Run" oven at low temp for short periods of time, several times to dry.PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Originally Posted by DSWHouston, We have ignition and are go for launch! The only problem is you've got your rocket upside down!
Reply:Originally Posted by MoonRiseWaiting to see how this all turns out.Ixnay (aka NO ) on using drywall/gib board for the top layer of your furnace/oven.  Once the paper burns on the dry wall, the 'chalk' (gypsum) filling has no real strength.  The gypsum won't really burn, but once the paper does the bricks on top will just crash right through.  Just creatively stack more firebricks on the top to close off the furnace/oven.Yeah, rust -never- sleeps.Speaking of which, you probably would NOT want to mechanically lock the firebricks into place in a steel structure because of thermal expansion.
Reply:I cleaned the area to be brazed and rounded out the area with a rotary burr.Original broken out sectionCleaned up in preparation for repair.One thing concerns me. Where the white lines are, which seem to be where the water level would have been with the shot bearings and seal, there's been a bit of corrosion. If I run my fingers around the hole in the centre, I can feel the thickness reduce as i pass the areas with the white lines. I can't measure the change in thickness and it may be 1/32" or less.Would I be better to clean that area right out to the white line?. At the bottom of the area I've cut out it's about 1/8" to the thicker outer body section."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375
Reply:Now THAT"S a whupaZZ table Tractapac! Belongs in "the forge".Once you get that complex section inside the firebrick it doesn't take much fuel to get it real hot. The speed you bring it up is important. I'll bring a heavy cast chunk up at better than 800°F per hour but something like that I'll limit it to more like 400°F. After all this work there's no need to hurry up and get it done.Matt
Reply:Originally Posted by Tractapac ...Where does the lxnay come from?
Reply:SimonThe areas I circled are points and will over heat easily, control your heat in thease areas carefully. This is doable but grinding points out and welding a patch that is oversized would have been a little easier to weld.When you make oven consider keeping casting as close to top as possible. You do not want to reach down inside to weld.Keep bucket of water close by. If torch tip over heats and starts popping, dip tip into water to cool for a couple seconds. I do not turn off valves because when I bring torch over red hot part it will relight ready to go. Does make a pop when it lights!Peter Attached ImagesEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Originally Posted by castweldSimonThe areas I circled are points and will over heat easily, control your heat in thease areas carefully. This is doable but grinding points out and welding a patch that is oversized would have been a little easier to weld.When you make oven consider keeping casting as close to top as possible. You do not want to reach down inside to weld.Keep bucket of water close by. If torch tip over heats and starts popping, dip tip into water to cool for a couple seconds. I do not turn off valves because when I bring torch over red hot part it will relight ready to go. Does make a pop when it lights!Peter
Reply:You can do it like you have it (patch) but cutting on red line would eleminate piont (hot spot). Make patch oversize because welding on edges creates hot spots also (yellow- I know I was drawing with laptop-ugly). After welding grind or machine excess patch off.Peter Attached ImagesEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:I cleaned the edges up as per the photos and cut a patch out and filed to shape. Built a form of temporary brick enclosure, then set up something to stand it on inside.Yet to decide on final clearance, any suggestions, please? !/8" diameter rod and similar gap?"Sliding" door to put the torch in through for heatingAbout 1-3/8" below surface of bricks.I'm wondering about making a bridge type of frame to suspend the patch from, maybe using the three bolts as shown and being able to fine tune its position. If I support it from underneath, it might be tricky to get the support out afterwards. Shown here sitting on a piece of 3/4" plate."One of the things we have to be thankful for is that we don't get as much government as we pay for." (Charles Kettering)Mitch 180 (NZ)Lincoln SAM-400-220 + ?-400 Fordson Major + 2 x Tractapac Humber 80 + Procut 40 PlasmaMiller Spectrum 375
Reply:Here's a thought.  Why couldn't a guy use some scrap iron pieces tacked in place on the bolts and on the patch to hold the patch in place.  You could just mig weld that up, and it would all be on the outside.  Then the patch would stay in place while your brazed the patch to the cast iron.  After the brazing and cooling was done, you could just cut your scrap iron "holders" out of the way, remove the bolts and your done.Last edited by Chuck; 09-10-2010 at 09:18 AM.Miller 250x & Lincoln V205-TSmith Oxy-Prop torch
Reply:+1 on getting rid of those 'points'.re: the fit-upNo so good.  Uneven and a bit much of a gap for a weld, waaaaay uneven and too much gap for a braze.  Braze typically flows in via capillary action to a -tight- gap of only a few thousandths (of an inch).  You've got spaces/gaps of what looks like 1/8 inch there!!!  The best laid schemes ... Gang oft agley ...
Reply:Moonrise - True in a manufacturing environment fit-up for brazed joints is held  at minimums, but with repair work, the Tractapac gap is no concern. With correct tinning and temperature, braze will easily wick over the gap. In fact, bridging the gap will make a good indicator that the filler is being correctly "worked" to wick and bond well; and not simply being "poured" over a minute cavity. Of course more surface equals more  bond and more strength. If this were a more critical repair I would suggest to  "V" the plate even more. Although with this application that's not of much concern.I wonder if the pump's shaft end should be left open to insure better heat convection through the pump cavity? However, that too is probably not so critical with this job.Good LuckLast edited by denrep; 09-10-2010 at 10:58 AM.
Reply:On the (few, not tons like probably castweld has done  or probably Alfred  has done too) braze repairs I have done, best results were always when the fit-up was pretty tight.  Tight as in usually just see daylight coming through the gap (a couple of thou), not big enough to measure with a ruler.    Gaps always caused problems in some way or another for me.  YMMV.  The best laid schemes ... Gang oft agley ...
Reply:The big problem with brazing over a tight joint design is that what often happens during a large repair is that the joint becomes re-contaminated. The contamination can be from "baked-out" flux run-off or other contaminants. Once a joint picks up contaminants, there is no way to get a bond without a thorough re-cleaning. Unfortunately, with a tight fit-up  it's  impossible to re-clean the joint. However, with an open "V" it's a simple matter to re-clean the contaminated area, using a carbide cutter for example.Of course this isn't an issue with small connections that require just one quick heat, thus such joints can be fit in thousandths of an inch.. Good LuckLast edited by denrep; 09-10-2010 at 12:04 PM.
Reply:Originally Posted by denrep(#1) In fact, bridging the gap will make a good indicator that the filler is being correctly "worked" to wick and bond well; and not simply being "poured" over a minute cavity. (#2) Of course more surface equals more  bond and more strength. If this were a more critical repair I would suggest to  "V" the plate even more. Although with this application that's not of much concern.Good Luck
Reply:seems to me it would have been a lot ez-er to just fab on another water pump, almost any water pump, even a electric pump, to pump the water, that's all it's doing right? just circulating the cooling water.
Reply:Originally Posted by denrepMoonrise - True in a manufacturing environment fit-up for brazed joints is held  at minimums, but with repair work, the Tractapac gap is no concern. With correct tinning and temperature, braze will easily wick over the gap. In fact, bridging the gap will make a good indicator that the filler is being correctly "worked" to wick and bond well; and not simply being "poured" over a minute cavity. Of course more surface equals more  bond and more strength. If this were a more critical repair I would suggest to  "V" the plate even more. Although with this application that's not of much concern.I wonder if the pump's shaft end should be left open to insure better heat convection through the pump cavity? However, that too is probably not so critical with this job.Good Luck
Reply:Originally Posted by TractapacThe tinning flux I've got states "only for cast iron", and I was thinking of making the gap sufficient to allow tinning of the cast iron and then adding the insert and doing the join.