Tig Welding Silicon Bronze

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Any bronze experts out there?I've got a broken rudder support housing to repair.  The housing supports the bearings for the rudder post and packing to provide a water tight seal.It's a little more complex than this, but think of a 2 1/2" bronze pipe mounted vertically to a 1/2" bronze plate.  The part (cast bronze) has failed where the vertical pipe meets the horizontal plate.Checking filler material, it appears that I have two choices of filler.  The silicon bronze filler meets the base metal test, but has a rather low tensile strength (58,000 psi-per Crown Alloys).  The other option is to use aluminum bronze filler (77,000 psi-Crown ALB-10-2).According to Crown Alloys tech data sheets, ER CuAl-A2 is recommended for it's fill capability.  Anyone have any experience with this filler, and if so, a recommended supplier.My intent is to run a tig bead around the outside of the vertical pipe/horizontal plate.  Then I will go ahead and silver solder the inside seam (not enough room to run a tig bead on the inside).  The interior brazing should fill any voids left after tig welding.Bottom line, I guess I'm looking for someone with experience with aluminum bronze filler and for a source where I could buy a small quantity.I spoke to Airgas about the Crown ALB-10-2 and they indicated that they didn't "stock" the item, but that I could order it.  The catch is that the minimum order is 10# at $15/lb and a tacked on handling fee.  I only need < a pound.The other option is Harris ALB-A2 which has similar specs.Any comments?Last edited by SundownIII; 12-20-2010 at 01:05 PM.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:No experience with Aluminum bronze but I have used Silicon Bronze extensively for sheet metal work on vehicles. Try weldingsupply.com for small quantities of filler. They will sell by the pound. https://weldingsupply.securesites.co...:terms::PE#E05http://all-a-cart.comWelding Cart Kits and accessories
Reply:Ditto on the SiBnz. I was / is approved for roll cage fabrication and suspension work with the NHRA and SCCA I would bet the SiBnz good enough. But I'm in Alaska and don't have to deal with it returning.
Reply:Silicon Bronze here.  We use a few hundred pounds a year and get them from the LWS.  I recommend using a flux (Stay-Silv white brazing flux) and preheating to ~500°F.  Stainless steel brush only, 2% Thoriated tungsten, ground to a point.Maybe this is more info than you needed.  If not, I have plenty more.Fegenbush
Reply:Can you add gussets to support the tube and take some stress off the weld?
Reply:Guess I'm about a +4 on the ERCuSi-A family. Should go down at 50-60Ksi and develop an attitude pretty fast with a little peening.Cyberweld shows 3# qty for $42 on the SiBronze.I've never seen the aluminum bronze used, maybe it's used for ampco bronze repair or something. Ampco is a whole different beast when machining and will not cold work at all, makes beryllium seem like fun....Matt
Reply:ZT,Input greatly appreciated.I had silicon bronze rods in stock (3/32 & 1/8).  Did not have the Aluminum Bronze.Now I've got a # of each (3/32 & 18) headed my way. (about $15/lb)I'll let everyone know how it works out.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Sundown,you might want to e-mail or call BB-396 on the left coast. Works with a whole lot of broken down, salt water melted stuff too. Esab/Lorch ET-220iEsab 160i caddyThermal LM-200 Lincoln feedersThermal Pee-Wee 85sThermal 60i- 3phase /RPC powered (Beast)Thermal Drag-gun 35CINE 1500 Klutch 140i
Reply:Hey SundownIII,I am also curious as to your results. I keep SiBrz in TIG rod & MIG wire, although never had an application that leaned towards the AlBrz. Would like to see your results with some pics & weld parameters. I like your intention to sol-sol the seam afterwards....makes good sense.  Thanks...DennyComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:I'd like to hear how it works too. I looked at Crown and thought the chemistry looked familiar (similar to C61400 or Ampco18). Surfed over to Ampco and found the following stuff (they have ABS qually/certs for fillers also on the site). Never welded the stuff, seems it's used a lot though. It's gonna be darn tough when it's done.E/ERCuAl-A2 data here; http://www.ampcometal.com/common/dat...o_trode_10.pdfFiller metals page here; http://www.ampcometal.com/en/index.php?page=weldingGTA welding guide here; http://www.ampcometal.com/common/dat...rc_welding.pdfmain site here; http://www.ampcometal.com/en/index_us.php?page=homeMatt
Reply:Hello SundownIII, I believe "Propdoctor" has done extensive silicon bronze and aluminum bronze work. Maybe try PM'ing him and asking or search his posts. Best regards, Allanaevald
Reply:Hey Guys,I appreciate all the input.  Really helps.I've done a fair amount of work with silicon bronze (pump housings, steering arms, wheels, etc.).  Always used silicon bronze filler.  That's why I had 3/32 & 1/8 in stock.Due to the way this part failed, I was looking for the strongest filler that was compatable with the base metal.  Reseach showed a tensile strength of 58,000psi for the CuSi-A and a tensile strength of 77,000psi for the CuAl-A2.I ordered a # of both 3/32 and 1/8' CuAl-A2 (Harris brand but same specs as the Crown) from WeldDepot.  Should be here tomorrow. I've got some scrap bronze in the shop, so I'll give both a try before I hit the rudder post.To the poster that asked about gussets, I considered that but space is limited.  What I have decided is to add a fabricated SS brace (an open sided box if you will) over the rudder post and add a second pillar bearing there.  That will reinforce the whole setup and take most of the loading off the bronze rudder post.Looking at the rudder post as it came off the boat, it appears to have been broken for some time (pretty cruddy).  Boat owner has been complaining about it leaking for some time (rudder post packing), but it was impossible to tell what the problem was until we pulled the whole thing down.Just so people have a little better idea of the job, this is on a 52' Motor Yacht, powered by twin 450HP Cat diesels.  The rudder shaft that goes thru the rudder post bearing is 2" in diameter.  Lots of thrust on that rudder when the boat is operating at cruising speed.This will probably turn out to be a $300-400 repair, but a LOT cheaper than having new rudder support cast (a one off) since the post is no longer available from the manufacturer.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:most of the boat bronze i work use nibral rod (ERCuNiAllast i bought was 1/8 @21 bux a pound they didn t have 3/32 set machine as welding SS clean and goLast edited by prop-doctor; 12-21-2010 at 03:13 PM.idealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441
Reply:Have you checked with Buck Algonquin? They carry alot of running gear for boats of all sizes.
Reply:jwright,Appreciate the tip, but yea, I know about Buck Algonquin.Only been knocking around the waterfront, off and on now, for about 60+ years.This is an imported Motor Yacht and none of the running gear (shafts, struts, rudders, etc) was produced in the US.  BA doesn't have anything that comes close.Propdoc,Yea, Nibral is some tough stuff.  About the only material that will take the power of todays larger diesels.When Viking Yachts went to the 6 bladed wheels for the 61, we started having real problems with cavitation burns in the hub area where the blades met the hub.  That boat with the Twin Detroit/MTU Series 2000 diesels (2000 HP per side) was running out at a little over 46 Knots.  Not bad for a 61' sportfisherman but was playing havoc with the wheels.  Finally had to get a naval architect in from Newport News Shipyard (now Northrup Grumman) who specialized in submarine propulsion.  Ended up changing the strut slightly and moving a couple of the lifting strakes in the hull (required modifying the mold) to get a cleaner flow of water across the props.  When the props cost $26,000 a set, you don't want to burn too many of them up.Funny/shocking story:First 65' Viking with the Series 2000 engines I sold, I was bringing the boat down from NJ to VA to be rigged out (tower, electronics, etc).  We like to run a new boat out (max speed) to get a baseline for what effect the tower/rigging has on top speed.  Dropped the hammers.  Topped out at 44.6K.  That wasn't too shocking to have a 65' boat running over 50 MPH, but when I looked down at the digital displays and saw I was burning 228 GPH of fuel, I didn't leave it in the corner too much longer.  Her normal cruise is about 32 K at 120 GPH.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:When you say burn the prop, does it actually make a mark you can see?
Reply:I was going to say NiBrAl and someone has beat me to it.  NiBrAl gives better corrosion resistance in salt water and is used exclusively for propellers.  But, understand that propeller applications see fast moving salt water, rudder posts don't.  I deal with this stuff every day and I think rudder posts and stern tubes and whatever are aluminum bronze but I've never seen anything that says it.  I've never repaired anything below the waterline with silicon bronze.  Most of my repairs with silicon bronze are on iron and the bronze offers infinately more corrosion resistance.  I'm curious to see what others have to say about using it below the waterline.