sealing a cork carb float.

[eviltwin]

I have watched this thread and other similar ones here with great interest.

Tubs, 1.) kudos for your critical thinking, ability to think outside the box, and recognizing the possible importance of the nugget Jim passed to you. 2.) I also applaud your simple solution which is just test and see by submerging in a jar. Bravo! While the jury is still out on this, your work could solve a problem which is paramount to one spoke of the critical elements in the triangle of combustion (FUEL, spark, compression).

I was inspired to dig a little myself and found an interesting thread:

<a href=”https://forums.aaca.org/topic/254716-cork-float-for-brass-carburetor-seal-or-not/”&gt;

Interesting part to me was where it was suggested that cork does not absorb gas. Can you see if one of the three has absorbed any. Maybe weigh it and then wait a day or so to weigh it a second time?
Even more interesting was where it said that cork will dry out and eventually fail, Could it be that it was falsely assumed to be a fungal rot when it was actually just drying out (dry rotting?)? This poster speculates that the shellac wasn’t to prevent fungus or absorption, but to prevent drying. Interesting theory.
I also wondered if being fully submerged was preserving it. But consider this: there is air inside cork. It is porous, thats why it is great where buoyancy is needed.

[eviltwin]

I remember when you originally posted the jars a while back. been waiting on the results. Fun stuff.
Forum is nearly impossible to post on. Things get scrambled to the point where they are not what was intended, links and pics never seem to post correctly or at all.
Anyway, I have wondered if it also would be possible to make floats out of expanding foam insulation. Not sure if Great Stuff is gas resistant or not. Could spray into a pipe or some other mold about the size needed and trim after it dried. Weight would be a consideration, though.

• This reply was modified 3 years, 11 months ago by eviltwin.

[mr-asa]

It may have nothing to do with fuel resistance? It may be that they sealed the cork to make sure that if it had any loose parts it would prevent the pieces from clogging the jets.
You have to remember that these motors were not designed to last as long as they have.

For me, I’d probably use a 2-part epoxy specifically designed for fuel. Once they are are set virtually nothing chemical touches them.

Marine-Tex is supposed to have a good reputation with fuel
http://www.v8buick.com/index.php?threads/fuel-resistant-epoxy-immersion-test-very-interesting-results.307765/

[Ralph Simmons]

i have sealed corks using this in the past
LUSTREKOTE CRYSTAL CLEAR 3 TOPR 7501
it is used in model plane hobby
to seal the paint , spray 3 coats to cork
can be gotten at hobby shops,hobby lobby

[GLEN DEUTSCH]

Just going through my old threads and found this. Shellac was the original sealer. I have used it for years. No problem. One caveat DON’T EVER USE ETHANOL GAS. It will melt the shellac

[crosbyman]

update on crazy glue…which I have used in the past to seal cork floats

I just took apart a JW with a crazy glued float….. the stuff was peeling like a sunburned skin

conclusion… no more crazy glue suggestions from me ….

Joining AOMCI has priviledges 🙂

[amuller]

Thanks, Tubs.

If a cork float will retain it’s buoyancy without a coating, that would be better than a coating that comes off and glops up the carb.

I’ve often wished that outboard carbs had bowl drains.

On the facebook group, there are some sharp people there.

[Author]

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