tank coatings and cork float coatings

[amuller]

I’ve been reading about this here and elsewhere. Opinions and experiences are variable….

Doesn’t seem unreasonable to wonder if fuel mix, especially with "synthetic" oils, might be more aggressive to some materials than straight gasoline.

So I have a couple of OMC tanks I’d like to salvage. I know how to clean and degrease these and use phosphoric acid products. But as for tank linings–there is POR15, Kreme, Red-Kote, some 2-part epoxy products … others. And there is not using any coating. Suggestions from those who’ve gone down this road?

Likewise cork floats. As far as I can see the cork itself doesn’t seem to be attacked by fuel, but old coatings are. Years ago I saw many plastic foam floats in cars that had gotten saturated with gas, so I developed a strong preference for the old-style brass floats. Do the current Sierra floats hold up? Again, advice is all over the map.

Thanks for any guidance.

[vintin]

I’ve used POR15 on a couple of old RDE cork floats.

It looks really good, seems to seal well and even toughens up and binds together the cork.

Two coats and seems to add almost no weight to the cork.

Time will tell. I use E-10 fuel quite often and run the carb empty after every use.

[amuller]

Thanks. I ordered a pint of the stuff.

Alan

[beerman57]

Don’t run the carb dry, that just lets the little bit of fuel left evaporate faster, leaving the oil to gum up the bottom of the float bowl and the high speed jet.

[vintin]

quote beerman57:

Don’t run the carb dry, that just lets the little bit of fuel left evaporate faster, leaving the oil to gum up the bottom of the float bowl and the high speed jet.

Three years no problems but thanks for the heads up.

[amuller]

I tried this and the stuff seems impressive. Also, The Carburetor Shop (Jon and Sue Hardgrove) use it on cork floats and these folks really seem to know their stuff. If it stays intact in contact with ethanol-laced fuel I think it will be a good answer.

Item: On my can the lid was so tight that the can sides buckled while working it open. So it doesn’t seal well and will probably harden in the can if not used up promptly. Never seen this before. Anybody else encountered this?

Alan

[wedgie]

quote amuller:

I tried this and the stuff seems impressive. Also, The Carburetor Shop (Jon and Sue Hardgrove) use it on cork floats and these folks really seem to know their stuff. If it stays intact in contact with ethanol-laced fuel I think it will be a good answer.

Item: On my can the lid was so tight that the can sides buckled while working it open. So it doesn’t seal well and will probably harden in the can if not used up promptly. Never seen this before. Anybody else encountered this?

Alan

I found a POR paint can where I used to work, and it was extremely difficult to open. Mangled the lid in the process, but managed to re seal it. I’ll try to remember to ask the guy that replaced me if It’s still any good.

[sailor58]

I use airplane dope on cork floats. Two or three coats. You know the stuff you painted on the tissue paper skin of your balsa frame airplane models? Last time I bought some at a hobby shop the young man at the store told me they don’t call it dope anymore. Its now known as sanding sealer. It’ll stand up to hot methanol, nitromethane and caster oil, E-10 gasoline won’t touch it.
Larry

[phil-b]

Sanding sealer used to be the "primer" I used on balsa parts (nosecones of Estes rockets) before the paint.
Maybe it’s paint without the pigment?

[amuller]

quote sailor58:

I use airplane dope on cork floats. Two or three coats. You know the stuff you painted on the tissue paper skin of your balsa frame airplane models? Last time I bought some at a hobby shop the young man at the store told me they don’t call it dope anymore. Its now known as sanding sealer. It’ll stand up to hot methanol, nitromethane and caster oil, E-10 gasoline won’t touch it.
Larry

Been a long time since I made a balsa/tissue airplane. But my recollection is that the sanding sealer went on first, then colored dope, then maybe some sort of fuel proofing topcoat, what we would likely call a clearcoat these days.

Dope solvents are toxic and tend to turn people into dopes. Fairly comprehensive discussion here: http://www.airfieldmodels.com/informati … erials.htm

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