Brasing Cast Iron

Heat Houser · Jan 5, 2011

What do you use to plug a hole in a block?
Pulled the sleeves on the B Farmall and was scratching around in the water jacket area getting rust and scale out. Up near the front by the camshaft bore, it was very thin and I poked thru. I now have a small hole between the water jacket and the crankcase.
I was thinking about sand blasting the area to get to bare cast iron and then brasing it shut. Anybody had good luck doing this kind of repair?
Any suggestions?

Thanks

GeneMO · Jan 5, 2011

I would be afraid that the heat would be an issue. You couldn"t get the area hot enough to braze without having a problem cooling it down properly and slowly enought to not crack.

Could you drill a hole and put a bolt through it with rubber washers?

I have also seen old timers make a patch out of mild steel and bolt it in place with a gasket.

Maybe even drill a hole, thread it and screw a bolt in from the outside.

Several options. I am not sure if IB weld would work or not.

Gene

S2710 · Jan 6, 2011

Back in the 60ies I had a ford 312 the had water in it and it froze and cracked the block behind the flywheel and I had it brazed up and after I got it running I put some silver seal in it and it never leaked a drop. Maybe I just got lucky. Bob

Dusty MI · Jan 6, 2011

I'd look into using some epoxy or such.

Dusty

Dave Sherburne NY · Jan 6, 2011

Clean it up real good and use JB Weld. No pressure on that cooling system.

RodinNS · Jan 6, 2011

Would another block be so hard to find or expensive if you did?
Otherwise I think you'd want to get it good and clean/bright in the area you intend to braze, get the block hot in an oven (as hot as you can get it), then braze the area closed, then return it to the oven to equalize the temp again and slowly allow it to cool.
Keep in mind that I've never repaired a block. There are specialist shops out there that do nothing else and if it's rare and you want to preserve it you might be well advised to consult them/hire them to do the work. What I've suggested is just basic cast iron repair procedures.... I usually weld cast iron with a Sodel 35 nickle alloy rod but that's not likely a good fit for what you're doing.

Rod

jackinok · Jan 6, 2011

cast iron is fairly easy to braze if you can get it clean enough,and that would probably be a more lasting repair than jb weld,but jb weld would probably stay a long time.in my opinion though ,it may be worth taking the block down and having it vatted and cleaned up good so you could inspect it closely.if it were so thin there you could poke through it quite likely is weak somewhere else also.be a shame to spend all the time and money overhauling it and then have to tear it back down,,Just my opinion of course.

Joe(TX) · Jan 6, 2011

Torch brazing does not cause a heat issue or rapid cooling like arc welding. It is the best method for this repair.

David G · Jan 6, 2011

You will spend more time and money patching that hole than getting another block.

Welding man · Jan 6, 2011

I have made a lot of money in the last 35 years fixing things that others said couldn't be fixed. Locate yourself another block,just in case, you can't fix it. Try brazing it, it probably will work, if it doesn't, go get the other one. You had a scrap block to start with, if it doesn't work, you still have a scrap block. Nothing ventured nothing gained.

rad · Jan 6, 2011

Back in my ill begotten youth (early 60s), I had a go kart with Model A transmission. It had a hole in its side due to something loose inside that broke through it. I used a carbon arc torch connected to our Lincoln tombstone welder to braze a patch over it. It lasted through the three of us brothers (about 8 years) before we moved on to automobiles. Never failed and we beat the living daylights out of that go kart.

So in my experience, braze it and save tha junk block.

D.B. in Mi. · Jan 6, 2011

The antique shop I go to for work uses JB Weld alot with excellent results. And for some reson my wife swears by it.

trucker 40 · Jan 7, 2011

Your best bet is to try and find a used block.The reason is because you poked a hole in one place,but if its that thin somewhere else ,it could get another hole in it.I dont know what it would cost to have a machine shop cut it out and make a sleeve,if they can.

Brasing Cast Iron

Heat Houser

Member

GeneMO

Well-known Member

S2710

Well-known Member

Dusty MI

Well-known Member

Dave Sherburne NY

Well-known Member

RodinNS

Well-known Member

jackinok

Well-known Member

Joe(TX)

Well-known Member

David G

Well-known Member

Welding man

Well-known Member

rad

Member

D.B. in Mi.

Member

trucker 40

Member

Similar threads