Painting a used plastic gas tank- Fuel resistant coatings?


ws6transam

Member
Nov 17, 2005
309
0
Hi everyone,
I'm attempting to restore a 1992 Yamaha WR500. It's a white bike, blue seat, pink and blue graphics, typical early nineties type stuff.

The fuel tank is in good shape, but it has yellowed with age and long-term exposure to petrochemicals. I'm going to order some new decals and apply them, but I do not want them to peel off due to fuel exposure. In addition, I'd like to restore the tank to the color white!

I've been looking around for some fuel resistant coatings, and seen some good candidates from PPG Aerospace, for use on fuel tanks and fighter jets & stuff like that. However I am skeptical that I will be able to buy in "quart size" like what I'd need for a fuel tank respray.

Have any of you been able to repaint a plastic tank and manage to keep the paint intact over the long term? If so, what kind of paint was it? I have an HVLP spraygun so I can use two-part epoxy paint for the job. Arctic White is the color I want. Ultimately it would be handy if I can paint the frame as well--- That would be bonzer.

One possibility that I'm looking at is the coating of the inside of the tank with a 3M product that's used in aerospace. It's EC-776 as found in this datasheet:
http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTt4xTt4x&EEVuQEcuZgVs6EVs6E666666--

The amber coating can be used in a "fill & drain" method where you put it in the tank, slosh it around, and pour it out, followed by a drying cycle via air hose. After sealing the inside of the tank, the outer surface of the tank should stay hydrocarbon free and not lift up the fresh paint and decals.
 
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txsbuckeye490

Member
Dec 27, 2008
14
0
look at bluelightning zoovy lined my 82 490 ,78 400 82 250 tanks with this & no problems with paint peeling, btw i used krylon fusion paint on the tanks they have the perfect match to YZ Yellow
 

ws6transam

Member
Nov 17, 2005
309
0
Blue lightning seems to be the unanimous opinion.

Thanks!@
I have new stickers on the way, and the tank has been airing out now for about a month. I'll give it another month or so, then swish it out with degreaser & coat the insides of the tank. I'm not sure if I'll paint the tank white yet, or not as although it's yellowed a bit, it's not super-terrible. I'd rather live with discolorization than risk a scratch & peel after downing it on a few trails. Fusion looks the goods though.... It's just I am very gun-shy on any paint that comes out of a can. I've never had any luck with it sticking, even after hours of surface prep, or with heat curing.
 

Jaybird

Apprentice Goon
LIFETIME SPONSOR
Mar 16, 2001
6,452
0
Charlestown, IN
The plastic friendly paint will seal the tank and help to keep the gasses from permeating the plastic and bubbling your graphics. If you don't paint it white, a good coat of clear coat before the graphics would be a good move.
 

shane Arnold

Member
Jan 3, 2009
6
0
Wow..I have a WR500 and I restored it as well.
I used krylon paint and it bubbled up on the gasd tank quickly.
Everywhere else it held up beautifully. What I would do is paint it and get a custom tank cover fab'd up by a seamtress.
Cause the gas tank is the hardest.
Also if it is yellow sand it really well. The tank is super thick plastic, mine was all beast up and scared from the edges,I sanded the deep scratches completely out.

If you can give me your email so we can discuss this particular bike, that would be great. Ive been through 3 top ends getting it to run right, and now I have no spark.

Hopefully we can assist each other in completely restoring the great bike.
 

ws6transam

Member
Nov 17, 2005
309
0
Hi Shane,

You can email me anytime you want: dburk %at% ws6transam %dot% org will work.

Anyway, you all convinced me. I took my tank and rubbed it down with 600 grit, then 1000 grit sandpaper, wiped the whole thing down with enamel reducer in order to make sure it's wax and oil free, then painted it with white Krylon Fusion paint.

The tank has been open and drying for six weeks and will not see fuel for probably another four weeks. I have ordered the Blue Lightning tank sealer and will coat the inside thoroughly before doing anything else. It's looking really nice I think, much better than the yellow.

The graphics are in the mail from yzgraphics.com and I will install them once everything has had a chance to cure. In late January I will be taking the bike to a dyno shop and doing some power testing, and tuning with a wide-ratio O2 sensor in order to get the jetting dialed in. I'll be running 50:1 Amsoil Interceptor synthetic so it looks like I'll need to lean it out a bit. Any suggestions as to where to go in terms of jetting? The engine is fresh and stock, save for the +.040 piston, Procircut pipe, and FMF muffler

WR500_jan3a.sized.jpg
 

gifthopsduane

Member
Dec 8, 2008
11
0
Fusion is an excellent choice for plastic... dust few coats, then a semi thick, I let it float out into a smooth surface, works great for me! Although it won't hold up to gas spilling on the tank.. haven't found one that does. I reconditioned my daughters XR80 (white plastic..) with a Scotch bright pad and Soft Scrub with bleach... worked great, took out most of the yellowing.. I found this trick way back in the days of football, we had white helmets.. great for game day. This also saved me from having to paint the fenders too.. also pick up a few cans of brake clean (the non-chlorinated type..) used with scotch bright (i like the no scratch green one) works well, will remove stickers too.. good luck.
 

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