The Ford Barn

32Bee · 08-11-2018, 08:40 AM

A curiosity question. How hot do exhaust manifolds get. JB Weld is only rated
at 550 degrees. That suggests to me that it's the temperature at which it will
start to melt and be of no use.

lotsagas4u · 08-11-2018, 09:01 AM

Are yours cracked? Why fix them? They are easily found.

JSeery · 08-11-2018, 09:03 AM

Typically somewhere in the 1000 to 1500 deg range. It depends on a lot of factors and can vary. No data to back it up, but I would guess a flathead would run somewhat cooler because of the exhaust path through the block.

Charlie ny · 08-11-2018, 09:08 AM

Peter,
An ancient fix for some exhaust leaks is.........WATER GLASS.........I think
it is sodium silicate or some such technical name. Both exh manifolds on my '35 were
warped on the block face, I coated the faces with this water glass stuff and that
was the end of the leaks. No good for broken flanges.
Anyhoo I got the WG at NAPA after finally talking to an old time counter man
who knew just what I was talking about.
Charlie

32Bee · 08-11-2018, 09:20 AM

Thanks for the info. They can get a lot hotter than I thought.

Peter

tubman · 08-11-2018, 09:22 AM

Sponsored Links (Register now to hide all advertisements)

JB Weld offers not one, but two high temperature epoxy repair products. I think their highest rated one is 2500-3500 degrees Fahrenheit. I use it to fill some pits in the quench area of an Edmunds head when I clearanced it, and it seems to have worked fine.

glennsanders · 08-13-2018, 05:20 PM

Just buy good used one , not that expensive.

Kurt in NJ · 08-13-2018, 06:04 PM

I have "fixed" cracked manifolds with furnace cement ---and sometimes a tin cover held with hoseclamp to give the patch support ---

Kube · 08-13-2018, 07:09 PM

I have to agree with others that have suggested buying a replacement. They are plentiful and reasonably priced.
And hey, if your manifolds are getting to 500f, you have some major (other) issues going on.

Jack E/NJ · 08-13-2018, 08:14 PM

>>>And hey, if your [exhaust] manifolds are getting to 500f, you have some major (other) issues going on.>>>

1500°F. Jack E/NJ

Jack E/NJ · 08-13-2018, 08:19 PM

Kurt>>>I have "fixed" cracked manifolds with furnace cement>>>

Yep. Works great. Jack E/NJ

GB SISSON · 08-13-2018, 09:24 PM

I buy them at the last day of a swap meet for 5-10 bucks apiece. So many folks build for speed or show and a stock manifold is not a hot seller. I do like the tin can lid for reinforcement though.

bobH · 08-14-2018, 12:46 AM

Quote:

Originally Posted by Charlie ny

Peter,
An ancient fix for some exhaust leaks is.........WATER GLASS.........I think
it is sodium silicate or some such technical name. Both exh manifolds on my '35 were
warped on the block face, I coated the faces with this water glass stuff and that
was the end of the leaks. No good for broken flanges.
Anyhoo I got the WG at NAPA after finally talking to an old time counter man
who knew just what I was talking about.
Charlie

I got water glass through a local drug store. Had to order it.
Also ancient use.. in the radiator to seal small leaks.

08-11-2018, 08:40 AM	#1
32Bee Senior Member Join Date: May 2010 Location: Stratham, NH Posts: 233	Early V8 Exhaust Manifolds & JB Weld A curiosity question. How hot do exhaust manifolds get. JB Weld is only rated at 550 degrees. That suggests to me that it's the temperature at which it will start to melt and be of no use.

08-11-2018, 09:01 AM	#2
lotsagas4u Senior Member Join Date: Apr 2011 Location: Plainview, Texas Posts: 757	Re: Early V8 Exhaust Manifolds & JB Weld Are yours cracked? Why fix them? They are easily found.

08-11-2018, 09:03 AM	#3
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: Early V8 Exhaust Manifolds & JB Weld Typically somewhere in the 1000 to 1500 deg range. It depends on a lot of factors and can vary. No data to back it up, but I would guess a flathead would run somewhat cooler because of the exhaust path through the block.

08-11-2018, 09:08 AM	#4
Charlie ny BANNED Join Date: May 2010 Posts: 3,019	Re: Early V8 Exhaust Manifolds & JB Weld Peter, An ancient fix for some exhaust leaks is.........WATER GLASS.........I think it is sodium silicate or some such technical name. Both exh manifolds on my '35 were warped on the block face, I coated the faces with this water glass stuff and that was the end of the leaks. No good for broken flanges. Anyhoo I got the WG at NAPA after finally talking to an old time counter man who knew just what I was talking about. Charlie

08-11-2018, 09:20 AM	#5
32Bee Senior Member Join Date: May 2010 Location: Stratham, NH Posts: 233	Re: Early V8 Exhaust Manifolds & JB Weld Thanks for the info. They can get a lot hotter than I thought. Peter

08-11-2018, 09:22 AM	#6
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,315	Re: Early V8 Exhaust Manifolds & JB Weld Sponsored Links (Register now to hide all advertisements) JB Weld offers not one, but two high temperature epoxy repair products. I think their highest rated one is 2500-3500 degrees Fahrenheit. I use it to fill some pits in the quench area of an Edmunds head when I clearanced it, and it seems to have worked fine.

08-13-2018, 05:20 PM	#7
glennsanders Senior Member Join Date: Jul 2014 Location: Sharpsburg md Posts: 480	Re: Early V8 Exhaust Manifolds & JB Weld Just buy good used one , not that expensive.

08-13-2018, 06:04 PM	#8
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,159	Re: Early V8 Exhaust Manifolds & JB Weld I have "fixed" cracked manifolds with furnace cement ---and sometimes a tin cover held with hoseclamp to give the patch support ---

08-13-2018, 07:09 PM	#9
Kube Senior Member Join Date: May 2010 Location: Wisconsin, USA Posts: 9,001	Re: Early V8 Exhaust Manifolds & JB Weld I have to agree with others that have suggested buying a replacement. They are plentiful and reasonably priced. And hey, if your manifolds are getting to 500f, you have some major (other) issues going on. __________________ "I can explain it for you. However, I can't understand it for you".

08-13-2018, 08:14 PM	#10
Jack E/NJ Senior Member Join Date: May 2010 Posts: 2,173	Re: Early V8 Exhaust Manifolds & JB Weld >>>And hey, if your [exhaust] manifolds are getting to 500f, you have some major (other) issues going on.>>> 1500°F. Jack E/NJ

08-13-2018, 08:19 PM	#11
Jack E/NJ Senior Member Join Date: May 2010 Posts: 2,173	Re: Early V8 Exhaust Manifolds & JB Weld Kurt>>>I have "fixed" cracked manifolds with furnace cement>>> Yep. Works great. Jack E/NJ

08-13-2018, 09:24 PM	#12
GB SISSON Senior Member Join Date: Jan 2014 Location: Orcas Island Washington Posts: 4,929	Re: Early V8 Exhaust Manifolds & JB Weld I buy them at the last day of a swap meet for 5-10 bucks apiece. So many folks build for speed or show and a stock manifold is not a hot seller. I do like the tin can lid for reinforcement though. __________________ Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1947 Tonner Pickup (red) mostly stock with exception of a cummins 6at turbo diesel, 1946 Tonner Pickup (green) with 226 cu in 6 cyl flathead, 1979 Toyota landcruiser wagon, completely encased in 1947 Ford Jailbar sheet metal. Ok, cornbinder rear fenders..... 'Rusty ol' floorboards, hot on their feet' (Alan Jackson)