Rick_A

Rick_A

Well Known Member
I want to make a Proseal gasket around the FAB carb door mating surface. I would like to put to proseal on the underside of the FAB top plate and press down on it with the door and have the proseal NOT stick to the door.

What can I put on the door so that the proseal doesn't stick to it? Wax paper, mold release wax,...?
 
Rick_A said:
What can I put on the door so that the proseal doesn't stick to it? Wax paper, mold release wax,...?
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The idea sounds right and it may work. I have been around polysulfite for 20-years and have never needed to not have it stick. Your technique does work with epoxy and fiberglass so it should work with proseal and metal.

I am thinking that you may want to run some experiments to see what will and will not work.
 
Wet Seal (sp?)

That technique is called wet sealing. Good old vasoline works great on the surface you don't want the pro-seal to stick to.
 
Saran Wrap works. A lot of people built their tanks and found that the proseal between the rear baffle and skin spread the skins slightly, making for a poor fit back to the spar. Also, there would often be a bead of ooze at the rear of the baffle that would interfere with the spar. My technique was to cover the spar in Saran Wrap and cleco the completed tank to it before the proseal set. Then, when the proseal had cured, the skins were held in perfect position. The proseal at the rear of the baffle was 'smooshed out' (a technical term ;)) against the tank skin but the wrap kept it from sticking to the spar and it was no problem to peel the wrap away from the tank.
 
Rick_A said:
I want to make a Proseal gasket around the FAB carb door mating surface. I would like to put to proseal on the underside of the FAB top plate and press down on it with the door and have the proseal NOT stick to the door.

What can I put on the door so that the proseal doesn't stick to it? Wax paper, mold release wax,...?
Click to expand...

What you want to do is a widely used technique in the aerospace indusry. It is known as FIPS or Form In Place Sealing. Typically, an access panel (or cover) is treated with some non-stick parting agent, the structure to which the panel or cover is affixed is prepared by slathering it with a healthy layer of proseal. The access panel/cover is treated with parting agent. At least one RV builder has reported good results using teflon backed sticky tape. Choose your poison. A Google search will reveal any number of sources for a true proseal parting agent. Whatever parting agent you do settle upon, the cover is temporarily screwed into place. In the aerospace industry, fiber (non-stick) washers with a sticky adhesive on one side called "donuts" are centered atop the fastener holes between the structure and the cover before the proseal is applied. The donuts are essential in providing a uniform thickness to the proseal gasket. Even still, when attaching the cover, it is important not to overtorque the temporary screws or bolts holding it in place. The excess squeeze-out of wet waste proseal is immediately wiped away. After cure the cover is removed, the donuts removed from the dried proseal, the structure cleaned up, and the result should be a gasket-like layer of proseal that will provide lasting air-tight moisture protection.
 
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Being an ex-fiberglass guy, we always used Scotch clear packing tape as a release 'agent'. Epoxy separates easily from it. Try a small test by putting a blob of ProSeal on a piece of packing tape and see if it will easily separate in the morning after a good cure.
 
Vasaline

On the first try I used a generic Saran Wrap and discovered that ProSeal sticks very well to Saran wrap.

On the 2nd try, I used wax paper with a coating of a Vasaline like product that my wife had in her cosmetics drawer - the ProSeal did not stick at all.
 
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Silicone Grease works

Dow Corning #4 (the stuff you are supposed to use on oil filters) works great as a parting agent.
Don
 
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