High temp epoxy

[larryejoh]

What is the best high temp epoxy to use to build up my head for a 2 barrel mod? I've read JB weld but is there anything better?

 

[rbohm]

8) here is a page you might study;

https://www.epoxy.com/high_temperature.htm

 

[larryejoh]

Have you tried any of these?

 

[rbohm]

8) nope.

 

[chad]

There's a thread here somewhere.
Wonder if there's a search function kin nab it?

Talked about heat resistant to 1,000*, machinable... seemed like there were several companies & varieties w/in those companies...
Guys who lent their opinion were (1/2 of them) biased on use - AND yes, all better'n JB (altho they HAVE come up w/some variety lately).
Was it "Mpg" lookin for the same application as larryejoh needs BUT after a failure?

 

[CobraSix]

http://www.cotronics.com/vo/cotr/rm_adhesive.htm

I've used cotronics before with varying degrees of success. Some things worked great, others were a little too much for it to handle (as in, too much machining).

 

[parkwood60]

I used regular JB weld on my 1 to 2bbl modification and it is fine. We run our car in 24 hours of Lemons and we just ran all weekend earlier this month with the ambient temp around 105 and it never got hot enough for the JB to be an issue. The secret is to use as little as you have to.

 

[80broncoman]

If i was doing a 2BBL direct mount on a small six, I'd use 3-5 small tack(not over 1/2 inch long) welds with a nirod and then seal it up with JB weld. I think for the temps you are going to see JB weld will be fine.

 

[jimlj66]

If i was doing a 2BBL direct mount on a small six, I'd use 3-5 small tack(not over 1/2 inch long) welds with a nirod and then seal it up with JB weld. I think for the temps you are going to see JB weld will be fine.

Can you clairify what you mean by using tack welds? What is the function of the welds? I'm planning on doing this myself and am looking at all options.

 

[rbohm]

If i was doing a 2BBL direct mount on a small six, I'd use 3-5 small tack(not over 1/2 inch long) welds with a nirod and then seal it up with JB weld. I think for the temps you are going to see JB weld will be fine.

Can you clairify what you mean by using tack welds? What is the function of the welds? I'm planning on doing this myself and am looking at all options.

a tack weld is just a very short weld to hold something in place before final welding is done.

 

[jimlj66]

If i was doing a 2BBL direct mount on a small six, I'd use 3-5 small tack(not over 1/2 inch long) welds with a nirod and then seal it up with JB weld. I think for the temps you are going to see JB weld will be fine.

Can you clairify what you mean by using tack welds? What is the function of the welds? I'm planning on doing this myself and am looking at all options.

a tack weld is just a very short weld to hold something in place before final welding is done.

I guess I'm still confused. I know what a tack weld is, but what are we holding in place? From what I understand, we mill the manifold flat, hog out the hole for a 2 bbl carburetor and build up the low spots with epoxy. The adaptor (I don't have one yet but all pictures appear to be aluminum) then bolts to the manifold, to which we then bolt the carburetor. What are the tach welds for in this instance? As far as I know it is not possible to weld cast iron and aluminum together. I'm not trying to be a anus here, just trying to get it clear in my pointed little head.

 

[80broncoman]

I guess I'm still confused. I know what a tack weld is, but what are we holding in place? From what I understand, we mill the manifold flat, hog out the hole for a 2 bbl carburetor and build up the low spots with epoxy. The adaptor (I don't have one yet but all pictures appear to be aluminum) then bolts to the manifold, to which we then bolt the carburetor. What are the tach welds for in this instance? As far as I know it is not possible to weld cast iron and aluminum together. I'm not trying to be a anus here, just trying to get it clear in my pointed little head.

You are correct on that. No welding of ANY kind will bind Alum and anything with iron in it.
If you going with a alum spacer I'd just use J-B weld.

 

[xctasy]

I used regular JB weld on my 1 to 2bbl modification and it is fine. We run our car in 24 hours of Lemons and we just ran all weekend earlier this month with the ambient temp around 105 and it never got hot enough for the JB to be an issue. The secret is to use as little as you have to.

I use it to profile my old 170 head to suit the later model 200 E0 head fittings. JB Weld/Devcon is perfect if its supported and used sparingly.

 

[chad]

"...JB Weld/Devcon..."
my goodness, Devcon, I used that 40, 50 yrs ago, didn't realize it'd evolved into JB Weld (or is by the same company). I used it back then in a 2 sided hypoderm.-like syringe (I think). Flowed more than today's product. Hadn't even heard that name in yrs.
Interesting
but that was brittle when 'cured' so probably a different product.

One of the several JB Welds is high temp but none of the 3 or 4 I've seen is machinable I don't believe. Have you seen one that is?... it's very widely accessible around here. One 'finishes' grey, another black...

 

[80broncoman]

I think the JB Kwik (5 min set time) is machinable. And I also think it dries a little harder than the standard JB weld.

 

[Gene Fiore]

Maybe this might work for you?

http://www.cotronics.com/vo/cotr/rm_putties.htm