Vacuum Leak Under Carb

Hey Jim. I replaced those gaskets a couple of weeks ago. It made a world of difference. I ordered the gaskets from skidim. They were a little thicker than the standard automotive ones I've seen and they weren't paper.
My friend's father was an auatomive mechanic in the 70s. He told me to make sure the spacer plate is completely flat. He said it's aluminium and can warp. He told me to lay a piece of sandpaper on the garage floor and slide the plate across it then look at the plate. It should have tiny scratches evenly across the surface. If it's warped, the lower points won't contact the sandpaper and won't be scratched. If that's the case, he said to keep rubbing it on the sandpaper until it becomes completely flat.
Now, having said all that, I didn't do it. I put the gaskets on, tightened everything down and it didn't leak so I didn't worry about it.
What do y'all think of the above method?
A new spacer plate is only around $20.

Jim:

Jimbo is right on about how to ensure the wedge is flat. However, I would suggest you put the sand paper on plate glass as your garage floor is probably not very flat. Use wet/dry paper with plenty of water.

If you want to use a sealant, then I suggest Hylomar. It is a blue sealant that never gets hard and you can easily remove the carb and reseal many times. It was designed for such a purpose.

79...:

I generally agree with you, but if Jim wants to try a sealant, then Hylomar will avoid the pitfalls you mention. Only a very thin film would be required and Hylomar never changes properties so nothing would be able to "break loose" and clog anything. What it will do is fill the voids caused by uneven surfaces. You can even remove and refit the parts without reapply the sealant and it will seal again.

FWIW: Hylomar was developed for the avaition industry. Specifically service covers on jet engines that must be sealed. The sealant allows the covers to be removed and reinstalled with reapplying the sealant. It is truely amazing stuff.

I've never usaed the stuff but it sounds like it is more of a rubberized coating than sealent. It's just most of the time everyone gets a little happy with the RTV and applies more than is needed, just a word of caution more than anything else. Usually if you use quality gaskets and prep the surfaces correctly then there isn't a problem with leaks.