Carb heat insulator resurfacing

[dmtfab]

I am battling a vacuum leak at the carb heat insulator where a previous owner used a grinder to remove the gasket material from the heat insulator. I can’t get a good seal because of the slight dishing of the sanding marks.

I know it looks like gasket material left behind. I have no idea what the tan stuff is if it’s not gasket material, but a razor blade won’t touch it. I soaked the insulator in my parts washer hoping the tan stuff would absorb and lift a little. Nope

So I tried running it as is, but I still get a vac leak on the primary opening where the phenolic is visible:

I don’t want to try to sand the remaining tan stuff off because I think I’ll just make stuff worse. I know I can but a new insulator, but I want to see if I can get this one cleaned up first.

Any ideas?

 

[dmtfab]

Has anyone milled the surface flat again?

 

[charliemeyer007]

Buy a tube of Avaition Permatex Type B Non hardening. Squeeze a nice fat bead on both sides, try not to let it squeeze into the carb bore, better to have it ooze out around the perimeter so you can scrape it off.

Form A Gasket Sealant | Permatex®

Non-hardening sealant for joints needing disassembly. Fuel and oil resistant. Classic Permatex blue.

www.permatex.com

Sand paper and a sheet of glass make a nice quick flatting device. Rub in figure 8's.

 

[CruiserInProgress]

I had a similar issue with my insulator. There appeared to be a gasket on the bottom side (against the manifold), but it had chipped off in a couple places. I ended up chiseling off what I could, then used flat files (coarse, the fine) to take off the rest.

It took a while, checking against a flat surface as I went, but eventually it was flat and smooth again. I used new gaskets on both sides and it sealed fine.

 

[dmtfab]

Buy a tube of Avaition Permatex Type B Non hardening. Squeeze a nice fat bead on both sides, try not to let it squeeze into the carb bore, better to have it ooze out around the perimeter so you can scrape it off.

Form A Gasket Sealant | Permatex®

Non-hardening sealant for joints needing disassembly. Fuel and oil resistant. Classic Permatex blue.

www.permatex.com

Sand paper and a sheet of glass make a nice quick flatting device. Rub in figure 8's.

I have some #2 in my cabinet, gonna find a suitable piece of glass. My wife does stained glass, hopefully she has a smooth piece she won’t miss…

I had a similar issue with my insulator. There appeared to be a gasket on the bottom side (against the manifold), but it had chipped off in a couple places. I ended up chiseling off what I could, then used flat files (coarse, the fine) to take off the rest.

It took a while, checking against a flat surface as I went, but eventually it was flat and smooth again. I used new gaskets on both sides and it sealed fine.

If I can’t get a small piece of glass, this sounds like a plan.

 

[charliemeyer007]

Yard sale picture frame or small window.

 

[pb4ugo]

I've done the glass and ssnd paper trick on different type of materials in the past with good results.

 

[bhsdriller]

If you don't want to mess with it or can't get it right they sell them new still

 

[cruisermatt]

get a new one and be good to go for another 45 years

2F Carburetor Gasket / Insulator / Heat Shield

This component serves three functions: it provides the gaskets to seal the connection between the carburetor and intake manifold, functions as a heat insulator for the carburetor, and acts as a heat shield protecting the vacuum and fuel lines. IMPORTANT: Install this part dry without any sealant...

cruisermatts.com