Antique cast iron welding fix

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Okay guys I have been on you tube and looking through the search on this Site and cannot find anything for what I am doing. My uncle handed me an old cast iron decoration piece that hangs on the wall. So far all of the stuff I saw while searching was for bigger and more mechanical type parts that get alot of stress work....? This thing will just hang on the wall only. Unfortunately it broke in half and he wants it fixed ( been in the family along time). I have never done cast before but from what I've been reading 309 , silicone bronze, or using o,a,torch setup for brazing with a certain kind of filler.??? My brazing experience  is very very little. Pre heat and post as well I assume?... What would be the best and easiest method for me to fix this decorative wall hanger.Thank you.          James        Precision tig 225Millermatic 185 w/ spoolgunLincoln 140Dewalt cold saw
Reply:I think to preserve the original appearance, and depending upon the actual size of the outer "rails", I might consider drilling longitudinally into them at the point of the break, and joining them with a couple of pins and JB Weld, sort of like you would fix a broken chair with wooden dowels and wood glue.I can't believe I just said that, and call myself a weldor!Bad idea?
Reply:He tried the jb weld already with no luck. I would have a hell of a time trying to get all 3 spots to line up exactly by pining them together. He is going to paint it anyways.Precision tig 225Millermatic 185 w/ spoolgunLincoln 140Dewalt cold saw
Reply:In that case, do it the easy way...Nickel rod, preferably. Possibly 309, it is pretty ductile, and will therefore mitigate somewhat, the effect of shrinking metal.Bevel -Apply small welds, peen, cool, repeat.Rule of thumb:If you aren't going to preheat, keep it cool(but don't cool it), if you preheat, keep it hot.Peen either way.Or just get out your mig welder, tack it up, and hope the welds don't simply separate from the base metal.Last edited by geezerbill; 03-02-2014 at 02:04 PM.Reason: Clarification.
Reply:I seem to recall "Lanse" here (aka: "ChuckE2009" on YouTube) made a cast iron fix on a vise using 7018 and some pre/post heat and it worked!   I also recently read in an old Lincoln book I have (circa 1950's) about farm welding and how to "cold weld" cast iron.  Do a little more google research on it but basically it explains that one must ensure the piece is at least 70 degrees F prior to welding.  Then apparently small little weld beads (like less than an inch) can be made.    Then allow the piece to cool to where you're hand can touch the cast iron before you continue on, repeating the (long and slow) process over and over again until the joint is welded up.In your case however, your wall-art piece weld joints would be  extremely small.  Perhaps you can use some 3/32 7018 if you don't want to purchase nickel-rod and basically tack weld the joint from the back side.  That way the welds won't be seen from the front when it hangs on the wall.  Try to do a small bevel in the joint but take it easy with the grinder.  Then hit the joint with a 3/32" 7018 tack weld.  Like you said, it's going to just hang on the wall as a decoration only, so there is no "critical" weld with the proper pre/post heat and Nickel rod requirement that I can see.   That's what I would do, since JB WELD didn't work for you.Lincoln Power Mig 216Lincoln AC/DC-225/125Miller  625 X-Treme PlasmaMiller 211 Forney 95FI-A 301HF 91110Victor Journeyman O/PMilwaukee DaytonMakita  Baileigh NRA Life Member
Reply:flat stock the same width as the rails extending about 2 to 3 inches either side of the break and some small bolts. heat is not your friend on this repair if you care for the paint scheme.i.u.o.e. # 15queens, ny and sunny fla
Reply:Butt the pieces together and soak in a little 50N silver brazing alloy.  Since the thing is painted the color mismatch of the metals will not matter.  If you use silicon bronze you will need to do a lot of beveling and then you will have to grind the repair afterwards to match the profile of the piece.  The 50N has a strong capilary action that will just draw itself into the break.
Reply:I kind of like docwelder's idea but hear me out.  Cut a piece of sheet brass or stainless the same size and shape as the rails and either pin the sheet to the casting or small screws to attach it.  Because JB weld is now on the broken pieces, it would have to be thoroughly removed before any brazing or silver soldering could be done and then you would have to color match so as not to see the repair.  By using a backing plate you only have to color match the crack.  Bob
Reply:I know someone is going to jump all over me for this butfor what it is, put slight bevel on ends - make sure partsare warm to hot - crank up mig - do sever tack welds -moveing from one side to other - then go back andconnect the tacks - no more than 3/8" at the timefixed a discharge maniford on a gas engine compressorlike this - it's still running - just my .02¢The main thing is not to panic or get excited Bobcat 250, X-Treme 12VS,  MM211Meltabo, Milwaukee,Porter Cable,Dewalt,MakitaVictor O/A, Ingersoll-RandEvolution Rage2, 40 amp PlasmaLincoln 225 AC/DC
Reply:Thanks for the replies fellers that would be the easiest way like doc mentioned, but the uncle would like to see it as original as possible. Like I mentioned he will repaint the piece anyways " I think he hates the colors" so doing full welds would be okay.I dont have any of other filler materials that has been mentioned all I have was 309 on hand for this project and really didn't want to get something that I might not but once or twice unless I had to. Silicon bronze was something I have been wanting to play with anyways so I hoping this was my excuse to get some. I haven't stick welded in years so this is not the piece. I know practice first, but this thing is only 3/8 thick and maybe 3/4 wide on the big pieces and it would be hard to grind all that weld on the face with the small detail stuff. I thought tig,  heat control and right filler it would be the right process.   Remember I am still learnin  and I appreciate the advice , that's why people ask before they do.Precision tig 225Millermatic 185 w/ spoolgunLincoln 140Dewalt cold saw
Reply:I have repaired several ornamental casting like that. I always braze w/ bronze.  Scraf the ends, clamp and braze with bronze.  Scraf so you don't affect the contact point and retain the original dimensions. Scraf leaving the longest point to match.  If painted, then wouldn't worry about color match.  Personally, I find brazing more controllable for such a small part, it is easy to cleanup and machine to size.I might check to see if the part is available, unless it is really sentimental ?
Reply:Originally Posted by RenagadeI know someone is going to jump all over me for this butfor what it is, put slight bevel on ends - make sure partsare warm to hot - crank up mig - do sever tack welds -moveing from one side to other - then go back andconnect the tacks - no more than 3/8" at the timefixed a discharge maniford on a gas engine compressorlike this - it's still running - just my .02¢
Reply:Originally Posted by tapwelderI have repaired several ornamental casting like that. I always braze w/ bronze.  Scraf the ends, clamp and braze with bronze.  Scraf so you don't affect the contact point and retain the original dimensions. Scraf leaving the longest point to match.  If painted, then wouldn't worry about color match.  Personally, I find brazing more controllable for such a small part, it is easy to cleanup and machine to size.I might check to see if the part is available, unless it is really sentimental ?
Reply:That's a brazing job, eight days a week.One method might be to grind the breaks clean, "tin" them all with whatever brazing rod you decide to use, line them all up against eachother, heat them all to melt the bronze/silver solder and push the pieces together so the joints end up as you want them. Some grinding to take care of the molten bronze/solder that got squeezed out and it should look as new if you got it lined up correctly.
Reply:A high nickel cast iron rod would work great. They are expensive, about $3 a rod but you would only need one. They won't pull on the cast as much as other rods and work best for things like this that a lot of weld can't be put in. Here is a picture of a cast iron heater that had 3 fins broke out and had to be welded back in. They are about the thickness of what your trying to do. They are welded with a 3/32, high nickle rod. Attached Images
Reply:vettersjake  -  I'm voting with Bob. Brazing works best when the joint has shoulders or is pocketed,not so well for butt joints.This is an easy and controllable repair if TIG welded with Nickel rod.  Construct an impromptu fixture so the members solidly butt; vee minutely past center from one side and weld.   Flip, vee just into the weld, weld, dress, and paint.Opus
Reply:That sounds better for me since my torch brazing skill isn't much to talk about. What about pre heat and post, keeping at an hotter temp. And slow cool down, do I need to do all of that? opus the ends are a little jagged but I can cut them flush. Thank youPrecision tig 225Millermatic 185 w/ spoolgunLincoln 140Dewalt cold saw
Reply:You don't really need to preheat or post heat, just peen well after you weld and don't do over an inch at a time before peening.
Reply:Tig weld with Ni-99 or 316L works a charm for me on machine parts if the customer is picky. Mostly I get the senior citizen crowd bringing the ornamental parts in, and I give them an AARP discount and use ER70-s2.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Originally Posted by BobYou don't really need to preheat or post heat, just peen well after you weld and don't do over an inch at a time before peening.
Reply:I think he means to hit it with a ball peen hammer to stretch the weld deposit some and relieve the shrinkage.