Van's Air Force
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fuel tank sealer
- Thread starter FLYIN9A
- Start date
LettersFromFlyoverCountry
Well Known Member
It's likely persistent operator error. Where is the particular location. Presumably you've sanded and cleaned all the components. What's the nature of the problem?
LOCATION
INBOARD, LOWER POSTERIOR CORNER OF R TANK, RV9A. YES SANDED, CLEANED ETC. SOME OF PROSEAL DOES NOT SEEM TO SET UP PROPERLY. I THOUGHT I WOULD TRY SOMETHING OTHER THAN PROSEAL AFTER THREE TRIES AND SEEKING RECOMMENDATIONS FOR ALTERNATIVE PRODUCTS.
JOE
INBOARD, LOWER POSTERIOR CORNER OF R TANK, RV9A. YES SANDED, CLEANED ETC. SOME OF PROSEAL DOES NOT SEEM TO SET UP PROPERLY. I THOUGHT I WOULD TRY SOMETHING OTHER THAN PROSEAL AFTER THREE TRIES AND SEEKING RECOMMENDATIONS FOR ALTERNATIVE PRODUCTS.
JOE
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Fuel Tank Sealer
I assume you are using the standard Van's tank sealant in a quart can. I had no trouble with mine, it always set up, sometimes it took a while. I used a postal scale and weighed every batch in the 10:1 ratio. Mix well, then mix some more. You shouldn't see any white streaks left, just uniform gray color. Make sure the tank surface is really clean, I used MEK after I alodined. Make sure the ambient temperature is per the specs. This stuff is fairly forgiving as long as it is mixed in the right proportions, mixed well and at the right temperature.
I assume you are using the standard Van's tank sealant in a quart can. I had no trouble with mine, it always set up, sometimes it took a while. I used a postal scale and weighed every batch in the 10:1 ratio. Mix well, then mix some more. You shouldn't see any white streaks left, just uniform gray color. Make sure the tank surface is really clean, I used MEK after I alodined. Make sure the ambient temperature is per the specs. This stuff is fairly forgiving as long as it is mixed in the right proportions, mixed well and at the right temperature.
longranger
Well Known Member
How much tiime are you allowing between assembly and pressure test? Even at 80-90 degF my sealant would still smear after 24 hours. At 48 hours it wouldn't smear, but was still tacky. I'd advise to wait at least a week before pressure testing; longer at cooler temperatures. You definitely wouldn't be the first to blow out an aft corner by pressure testing too soon.
Another problem might be too large a gap in the corner. Sam Buchanan installed gussets to close these up a bit. Check about 3/4 of the way down this page.
Another problem might be too large a gap in the corner. Sam Buchanan installed gussets to close these up a bit. Check about 3/4 of the way down this page.
longranger
Well Known Member
I was surprised too, Walt. Although too firm to work with, the sealant would still stick to and smear on a glove after 24 hours at 80 degF. After 48 hours, I could pull a "nib" of sealant off the end of a cleco and shape it, but no smearing - a bit firmer than silly putty. At this stage, two "nibs" rolled together would adhere to each other, but not meld together. It was over two weeks after final sealing before I got around to pressure testing; the sealant was hard, and I got no leaks.
Expiration date on the kit was Feb-2013, and I used a 0.1 gram-resolution scale to mix, although I do estimate about 10% of Part A left after running out of Part B. I started a new kit (exp March-2013) about half way through the second tank, but I wet-riveted this one, and didn't check on it for 4 days. It was fully cured by then.
LettersFromFlyoverCountry
Well Known Member
Joe. Looking for more information here. Are you encountering leaking when testing or have you not tested it yet and are just unhappy that it hasn't set up?
It sounds like you're talking about the corner of the tank and the baffle, right? You have to put A LOT of proseal in those corners before sliding the baffle down into place, so that it makes not only a nice seal, but creates a nice bead of proseal.
You say "some" of it doesn't set up . How long are you waiting. One tip is to stick a work light into the tank overnight. That heats the area up a little bit and speeds us the cure.
It sounds like you're talking about the corner of the tank and the baffle, right? You have to put A LOT of proseal in those corners before sliding the baffle down into place, so that it makes not only a nice seal, but creates a nice bead of proseal.
You say "some" of it doesn't set up . How long are you waiting. One tip is to stick a work light into the tank overnight. That heats the area up a little bit and speeds us the cure.
170 driver
Well Known Member
I used PRC Proseal from Spruce to fix my leak,,,I have many years experience with this brand while working for an oem,,,I have never seen it not set up if mixed properly or get soft after it has set up. It cost a good bit more but I didn't want to rework the leak again so I spent the money for it. These tanks were my first experience with flamemaster and probably my last. My opinions only,,,your results may vary...
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Walt
Well Known Member
PRC DeSoto is the defacto standard in the sealant world, however even when using this in a production environment, each batch would be tested to ensure it conformed to spec before being released to production.
So it's not a bad idea for you to test each batch of proseal before commiting it to a project. Just mix up a small amount and make sure it sets up in the allowed time frame, if not, then you're better off not using it on important parts like fuel tanks!
So it's not a bad idea for you to test each batch of proseal before commiting it to a project. Just mix up a small amount and make sure it sets up in the allowed time frame, if not, then you're better off not using it on important parts like fuel tanks!
