Gasket material choice for Rider Ericsson

[sshire]

I'm close enough to having all of the Rider Ericsson parts completed that I've been thinking about ordering material for the gaskets between the cylinder, base and hot cap. I'm assuming that this is to reduce heat transfer from the hot end to the cold end. 
The ultimate insulating material (easily obtainable) is Silica Aerogel. 
Silica aerogels have the lowest thermal conductivity of any known solid. 

However, the thinnest available in small quantity is 3.5mm in thickness. 

Is this too thick? The material does compress with a slight increase in thermal conductivity.

Is their another material suggestion that would be close in thermal conductivity?

[b.lindsey]

Stan, I know it isn't hi tech, but I used regular gasket material from the auto store...probably around .030" thick.  I honestly don't think it needs anything more even if more is better in this case.  Just my $.02

Bill

[sshire]

Gee, Bill. $2.00 gaskets. Sold. I wasn't super excited about $25 aerogel. It is very neat material though.
I'm off to Pep Boys or Autozone.

[mklotz]

Rats!...and here I was looking forward to a hands-on account of how one machines something that is what? 98% air?

[sshire]

Lathe with an air spindle?

[b.lindsey]

Stan, I usually copy a template of the needed gaskets from the plans if available, or draw them up in AutoCAD and print them and spray adhesive them to the gasket material. Then I use one of these sets to punch the holes. They are pricey but you can catch them on sale or with a good discount coupon. I use these often and they work well on brass shim stock up to about .020" or so.

Bill

[sshire]

Great idea. I'll draw them up tonight.
I do have that punch set. So much better than poking a pencil through the gasket

[b.lindsey]

Yep, good clean holes and with the clear die plate you can line the holes up more easily too. Should have known you had that   

Bill

[Ian S C]

     In places where I don't use Loctite gasket goo, I use gasket paper, cut it out just a little bigger than required, place it over the area that requires the gasket, and tap around it with a little hammer, including the bolt holes, or for these holes a large ball bearing over the hole and a light tap, and the hole is cut.
                        Ian S C

[sshire]

Ian
I must try that. Sounds like a nice technique.
I too am a fan of loctite gasket goo. I've used it on a number of engines and no air leaks.

[b.lindsey]

I have used Ian's method also, but you have to be careful tapping on aluminum castings or other softer metals with even a small hammer, it can leave some marred places if not careful. The techniques works well on CI and larger or full size engines though.

Bill

[sshire]

I get that. Sometimes looking at a brass or aluminum part mars it.
I've drawn the gasket patterns in Inventor and printed them last night. The punch set will be used after I get the gasket later today and spray glue the pattern to it.

[Admiral_dk]

Back in my youth when I tuned 50cc mopeds into MotoX "racers" (not by modern standards), I put oil on the surface I needed a gasket for an pressed the gasket paper onto it - that way I "printed" the area that should be kept.

For hole sizes that I did not have a suitable punch for, I used a compass / divider (what is the correct term ?) and instead of the graphite core it would take in the drawing leg, I put in a piece of round steel that was sharpened in one end and used it to cut the paper.

If I needed a gasket for the bottom of the cylinder, I used the method above and cut the big hole first and then put the remain against the oil smeared bottom of the cylinder and got the transfer ports + four bolt holes and outline.

[sshire]

More great tips for the gasket notebook. Thanks!

[mklotz]

Other additions to the gasket notebook...

Go to the craft store (e.g. Michaels) and check out the swivel-blade craft knives.  Handy in their own right, some of them have blades with a convenient ~1/16" pin attached that will fit the lead holder in the typical draftsman's compass.

The pen-holder attachment on Elmer's beam compass...



can hold an X-Acto knife (or a swivel knife) just as easily as it holds a pen or pencil.  Perfect for cutting larger radii.

Elmer's compass is a great tool by itself.  I've used mine often and my wife borrows it for laying out her grandkid birthday cake designs.