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Does Proseal Chemseal B2 TANK SEALENT STICK TO PLASTIC

gmcjetpilot

Well Known Member
EDIT: High-density polyethylene (HDPE) *tank materal*
I did try "plastic welding" using a solder iron. It worked mostly worked, looked good, but it seeps. Pin hole? Was not aggressive enough. This is where sealant comes in. I am going to try again.


As any builder knows proseal or tank sealant sticks to everything.

Will is work on plastic fuel tank? The sealant is primarily for metal, however if the plastic is clean, roughed up, it should stick?

ANY EXPERT OPINION (or wild guessing) Appreciated. :D
 
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I installed my NACA plastic cockpit vents with proseal. Inside of aluminum skin was already primed and painted. I roughed up the mating surface of the vents with sandpaper prior to mounting. Not flying yet, but they seem to be permanently installed.
 
I used it many years ago to add vents to these new ventless “green friendly” plastic fuel cans that have those silly push down to open spouts that spill fuel everywhere but in the tank. I drilled out some brass and rubber tire valves, drilled mounting holes for them, then pro sealed them in. Replaced the spouts with old fashioned replacements you can still buy. Holding strong many years later and no longer have to fuss with non venting cans when I use them.
 
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What specific material?

Some non-metallics would require flame passivation to allow a bond, then yes.

EDIT: Flame passivation is especially applicable to HDPE.
 
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Proseal/plastic

YES Short answer
I have a 2001 RV-6A the other guy built.. He put the cowl pins in from the inside the cabin through the NACA vent. Bad idea
My NACA vents were both broken beyond repair, because of this failed trick. I used a heat gun to warm the Proseal and peeled them off with a putty knife. Glued new in place with more Proseal. 25 year old stuff to boot. no special prep either.
Never let go in 20 years. New ones are a year or so old. White airplane, so painted the vents black after installation.
Your luck may vary Art
 
I repaired a plastic hydraulic oil tank on my boat about 22 years ago and still no leaking. No idea the type of plastic though.
 
Proseal

I have a can of Vans FlameMaster about 8 years old. I always mix a test before use. I fixed a leak on my Thermorest Mattress. Sealed the gaps on the Frankensnorkel. Many more odd jobs. It definately won't stick to a slick surface so abrade the plastic with 80 grit first.
 
EDIT: High-density polyethylene (HDPE) *tank materal*''

Of course it has to be fuel proof.
 
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I don't believe it would stick much to HDPE. Getting adhesives to stick to HDPE is very difficult.

hmmm, this seems like an opportunity for some tests.

I have some pieces of scrap HDPE around. When I get around to building my extended range tanks and break out the sealant, maybe I'll do some test coupons on HDPE bonding to various materials with the flamemaster sealant.
 
We had an old motorhome that had a cracked water tank that was HDPE. The official solution was to "weld" the plastic with some sort of heat gun device that laid down new plastic. There was no way to get the gun in to where the crack was. The guy who knew how to weld this type of plastic told me to just get some pure silicon aquarium sealant at the local big box store, slap a big wide layer on the crack then and use something to cover the silicon and crack. It worked great and we were then able to fill up the fresh water tank without getting the water contaminated with anything noxious. Once the silicon cured it was safe for fish, so it must be pretty inert.
 
UPDATE... I did weld repair (soldering iron). The tank injected molded seem has a flange of extra material next to the crack. I melted that into the crack. Tested with water, seemed sealed. Put epoxy over as belt and suspenders. I let it sit two days. Put it together and it worked for awhile. Ran the generator for 30 minutes, then let it sit pm cardboard for two days, and got a dinner sized gas stain

The tank is back ordered. Manufacture shows back ordered with no expected date. I will buy a tank ($80) if I can get one. If not I will grind the epoxy out and re-melt it more aggressively. I was a little timid at my first attempt. I will take the tank back out and give the weld repair another try just for fun, but a new tank is the way to go (if when I can get one).
 
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