Two part epoxy..

[peejay]

more likely the 5min stuff doesnt work as good. its compromised to make it set quicker. thats what ive found with epoxies in general

It's what I've found through experience in using it to modify intake manifolds, as well. The 5 minute epoxy is easier to work with but it doesn't have nearly the strength. It also seems to shrink with exposure to fuel.

I like to use the "quik weld" stuff for anything that needs to be HARD because it seals a gasket. The stuff that comes in a tube and you break off a piece and knead it. I also do like to give it something mechanical to lock into like some cuts with a Dremel or drilled holes or some sheetmetal screws, because I had some of the 5 minute stuff break loose in an intake port once and now I'm paranoid about everything.

[dhidaka]

From JB Weld website:
Original J-B Weld can withstand a constant temperature of 500º F. The maximum temperature threshold is approximately 600º F for a short term (10 minutes). Refer to individual product packages for more temperature information.

KwikWeld is a great alternative to original J-B Weld when you need a quick-setting epoxy. It sets in 4 minutes and cures in 4-6 hours, while J-B Weld sets in 4-6 hours and cures in 15-24 hours. Because it is faster setting, KwikWeld has about two-thirds the strength of J-B Weld; however, they are both strong enough for most projects and repairs.

[Walter R. Malik]

more likely the 5min stuff doesnt work as good. its compromised to make it set quicker. thats what ive found with epoxies in general

I was under the impression this was to be FILLER material for an intake manifold where adhesion and temperature are the only criteria ... strength is not the issue.
Now I see that everyone wants to interject their own criteria, not the OP's.

I guess I should realize, that is the normal practice here.

[Dave Koehler]

chuckle

[cgarb]

I have had trouble with JB weld getting soft when contact with fuel is made. My local machinist recommend me not to use it also. I have had good luck with Blue Magic quick steel. The label claims it's chemical resistant and has not softened as of yet on my intake where I used it as filler.

[peejay]

more likely the 5min stuff doesnt work as good. its compromised to make it set quicker. thats what ive found with epoxies in general

I was under the impression this was to be FILLER material for an intake manifold where adhesion and temperature are the only criteria ... strength is not the issue.
Now I see that everyone wants to interject their own criteria, not the OP's.

I guess I should realize, that is the normal practice here.

Adhesion strength is one of the ways in which the 5 minute version is compromised.

None of it is very "strong" structurally speaking. I wouldn't try to put threads in any of the pour-n-mix stuff unless it's something really big and coarse like a broom handle thread. The stick weld type stuff does dry hard enough that you can use it where you need to maintain a gasket surface.




The tab on the bottom is Quiksteel, hanging out to cover a port leading to the exhaust ports. Ran this manifold for years, never leaked and had no erosion.

One of my current projects is taking a manifold that someone cut the carb area out into a huge plenum, and filling all that back in so it is four holes again. Had to use a ton of the Quiksteel, and when it starts to get warm as it sets up, it gets HOT when you are working with a large amount of it! But it's the only thing I can trust to be able to be FILED down flat so the carb gasket will seal to it.