Missing weld on exhaust flange

[txboiler]

After getting exhaust back from ceramic coat I noticed an approximate 1” gap in the weld on the flange of the side pipe. The gap can be see in the upper left corner of each photo below. This is frustrating as I cleaned up the welds on the exterior, but didn’t notice this. Maybe it was the contrast of the light coming through the gap and the dark ceramic coat made it more noticeable.

Obviously, I could get this welded and recoated but I want to see if anyone has used JB Weld extreme heat, or similar product. The material spec claims it is good for 1000 deg F. Does anyone have other recommendations.

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[GoDadGo]

Get a shop to T.I.G. Weld the spot.
.....The J.B. Weld won't hold up.
..................Sorry!

Edit Added:

This is frustrating as I cleaned up the welds on the exterior, but didn’t notice this. Maybe it was the contrast of the light coming through the gap and the dark ceramic coat made it more noticeable.

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[Lickity-Split]

[QUOTE=txboiler;491600] This is frustrating as I cleaned up the welds on the exterior, but didn’t notice this.

Your comment implies that the exterior is welded as well as the interior? If so, I wouldn't worry about the gap on the inside. It should still be strong enough.

(But of course, my opinion is only worth what you paid for it.)

[rich grsc]

[QUOTE=txboiler;491600] This is frustrating as I cleaned up the welds on the exterior, but didn’t notice this.

Your comment implies that the exterior is welded as well as the interior? If so, I wouldn't worry about the gap on the inside. It should still be strong enough.

(But of course, my opinion is only worth what you paid for it.)
True, if the outside is welded, then no need to do anything else.

[txboiler]

The welds on the flange is only from inside. The welds I was referring to one the exterior were after the 4 tubes joined into the 1 in front of the “muffler”. I can see light coming through the area with the missing weld.

[MB750]

As been said, what's the outside welds look like?

FYI, exhaust temps are on the order of 1400F at the cylinder head, and don't cool much where you'd be putting the JB Weld.

[txboiler]

There is still some confusion with my original post. There are no welds on the outside in the area I noticed the weld was missing. The area with the missing weld is the flange that connects the side pipe to the ball flange collector coming from the headers. The missing weld on the flange of the side pipe are on the surface common the header/collector. I added a new photo with the area back lit and circled in red. I suspect I didn’t notice it when the pipe were unfinished because the bare steel is light in color and didn’t have much contrast.

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The welds I mentioned in the original post, that I cleaned up were on the exterior surface of the side pipe in the areas marked with red in the photos below.

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All that to say…

1) I plan to get it welded per Go Dad Go’s advice (that is what i suspected but was hoping for a different answer)

2) current builders might want to check this area by backlighting before you get them coated.

[Mark Eaton]

Agree. You could MIG or TIG that, no JB weld.

[CraigS]

Where is the weld when the header is in it's normal installed position? It may be difficult enough to see that you could have it welded and then touch up w/ rattle can exhaust paint.

[txboiler]

I am pretty certain (I am away this week and won’t be able to verify until later) it is on the upper outside corner; making it pretty visible. Welding is the way to go and I will make the decision on paint touch up or recoating with ceramic coat after I assess the weld.

[MB750]

I would drop a TIG bead on the inside of the flange to fill that hole. Good catch. Maybe this is why the Roadsters are so loud! :p

Bad craftsmanship there. :confused:

[Hoooper]

If you have that welded by a professional and not a muffler shop I dont think you will be able to tell from the outside that spot isnt coated, especially with the body on the car.