My '53 215-6 exhaust manifold was badly cracked. A fellow member here sold me another one, but now that it's sandblasted it's got a small crack as well. I can get it professionally welded by someone who can keep it heated in the oven, etc, but that's kind of a big deal. My question is, has anyone ever used this Fireseal 2000 epoxy putty? It's made by POR15 and claims it's the fix for such things. Any experience??

 

I bought an engine that's got some broken bellhousing mounting tabs and I was looking at what it takes to repair it. I found this web site

http://www.muggyweld.com/castiron.html

As an alternative, you might look at welding it.

 

Looks incredible...actually looks too good to be true....anybody every try that??

 

The first question would be, how are you going to use the truck? If it is a show truck that doesn't get run much, it will probably hold. If it is a driver that runs regularly and might "gasp" see a load, the manifold will get too hot for epoxy to stay there. I tried some industrial stuff that was supposed to take up to 1600* on a manifold of a Dodge class c motorhome, it held for about 100 miles before blowing out.

Jeff

 

We used some POR 15 putty to fix a cracked exhaust manifold and it worked fine. The big key is to let it set up until it is rock hard, at least overnight. It aint pretty, looks like a blob of putty, but this wasnt a pretty car anyway. If this is a truck you plan on popping the hood to show people, i would use something else.

JMO

Mark

 

I'd go the weld route if you expect to use it again. Once you put something else on it, especially something like muggyweld, you've likely lost any future repairability.
You'd be surprised at how many people bring in gold jewelry they (or some hammer mechanic) tried to repair with lead solder. They can't believe it when you tell them they just destroyed their jewelry.

 

I've heard of guys using an old bbq to weld cast iron. They put the part on the grill and get it as hot as the bbq will go. They then weld it and then every half hour they turn the bbq down a bit until it's as low as it goes. Then they turn it off and let it cool with the lid closed.

 

I broke off an ear on the 289 exhaust manifold in Teddy. Why didn't somebody tell be to take it easy or they will break off? The local welder charged me $40 to weld it back on. He also bolted it to a straight edge so that when it cooled off it would still be straight. Jag

 

That's the issue I'd have with the BBQ method, warpage. The flange would likely need surfacing after, a cost that would negate any savings on the welding.

 

I have had some luck welding to cast metals. Some castings take it pretty well other snap crackle and pop. For some reason every ford casting I have welded to has worked great (8.8 housing, turbocoupe wastegate housing) Dana housings were pretty crappy though. If you have a good 220v mig lay down a nice bead on your original housing and see what it does you should know in a few minutes if it will hold or not. Oh an arc welder with a high nickel rod would be even better than the mig.

I think the bbq is a good Idea I would think it would be difficult to warp a cast piece in 400 degree temp range.

Make sure you clean the piece good and I would grind out the crack a little also use a torch (a propane hand held works good) and pre heat the area. cast metal retains moisture as you heat it up it will probably sweat. the 8.8 sweated quite a bit.

 

It depends a lot on the alloy and its history. Are you talking about an e-xhaust manifold (it appears so)? It has been thermally cycled thousands of times, and the grains in the iron are bound to be affected by that. Those Muggy rods (and others) are a total crapshoot from what I've heard.

If there were a way to reliably weld c.i., every cracked flathead on the planet would be back on the road. It is simply not a reliable process and especially on an old exhaust manifold. Why not buy a set of headers, I'd guess the welding repair will end up costing 1/3 the cost of a nice set!

 

I have always brazed cast iron parts. The entire part has to me heated almost red hot tho for a good job. I use a ceramic Kiln. Some parts I have managed to braze just with a torch then let them cool slowly covered with asbestos blankets (have fun finding those nowadays). Every part must be checked for flatness tho and resurfaced if necessary, -which it usually is.

Commercial cast iron engines, big diesels, etc are heated up in an oven and brazed back together then cooled in an oven. Those engines are re-machined totally afterward.

There are some commercial furnace cements that might work on a manifold...