High temp engine fin repair???

[chuck hahn]

Has anyone fixed a scrubbed off fin edge? Whats a material that will withstand the operating temperature heat and be ok??? Basically I want to build out the scrubbed off area and reshape it again. Need to build it out about 3/16 inch.

I was wondering about JB Weld but not sure it will take the head heat.

[hampshirehog]

JB Weld will do the job fine Chuck. I've fixed much larger damage than that and it's lasted years. The usual 'prep is everything' applies.

If you're not painting the damaged area you can use that alloy weld stuff (that's more akin to a solder - I forget the name but there's several brands out there). I've used it a few times - I don't think I've got the technique right but it works for me if I weld on a blob and file it back to shape.

[chuck hahn]

Ive gone to Harber Freight and got those alumiloy low temp rods and tried it with the MAPP gas. Thing is that I cant generate enough heat due to heat migrating into the head...it simply wont get to the desired 730 degree point so the alimiloy will penetrate and bond.

Now if I knew someone with a set of torches like the instructions say to use on thick and big pieces then I would be golden. But I dont have access to a oxy / acetelene set.

[Gregory]

If needed I guess I can bring my acetylene set by on the way out of town Sunday

[Nessism]

I tried using O2 acetylene before and couldn't get the aluminum hot enough.

[chuck hahn]

The instruction sheet says to use a torch set if the metal is thicker than a regular propane torch can heat...which is obviously the situation. Says use the biggest tip and feather the flame so it applies ample heat to make it bond.

Its that or find a product that will allow me to rebuild the missing area, shape it, and be confident its not gonna fall off when the engines at operating temps.

[chuck hahn]

I can make it work on some 1/8 strap aluminum..but that gets hot enough because the heat isnt wicked away like that 60 pounds of head does. Its gonna take some industrail heat source to get the head heated well enough.

If you want to bring the torches Greg thats cool. No harm no foul for trying.

[Nessism]

Find someone to TIG it, then you can dress it down as it should be.

[chuck hahn]

Got the money for a welder ( to pay for it ) ??? I DONT!!!

[Nessism]

Glue a chunk of aluminum in place with JB Weld then like hh suggested.

[chuck hahn]

Ed..its only about 3/16 of an inach thats ground off....not enough for adding a piece. it needs a solid pad added that can be sanded and shaped. Ive never used JB Weld on a head and dont know of its heat profile.

I was leaning that way if I can get ahold of torches or the Alumiweld rods fail.

[rapidray]

Chuck, JB Weld will work fine. Ray.

[sharpy]

Got the money for a welder ( to pay for it ) ??? I DONT!!!

Buy a head and barrel from half way around the world that has perfect fins. Only costs u 600 bucks for shipping. Ask me how i know.

[chuck hahn]

The consensus seems to be that JB will do fine..so its what I will try today. I know it doesnt get that hot being on an outside edge, but ive never used JB for such an application...so I ask questions first.

[hampshirehog]

If you tape a strip of card flat to one side of the repair area you'll have something to work to plus it'll save you sanding down one side of the hardened JB Weld - especially useful if one side of the fin is more tricky to access than the other. It will of course stick to the filler but just pick it off with a fingernail or a piece of plastic, wetting if necessary.

There are different types of Lumiweld (or whatever the brand name is) and some melt at lower temperatures than others according to my google search. The alloy I have in the garage is a 'no-name' make but it melts pretty easily with a MAPP torch. The stuff you have might be a higher strength / higher melting point product.