fiberglass gas tank

[tmc3c]

Has anyone had to patch a fiberglass tank?I have a small spot where the fork came in and caught the kill switch wire between tank and cracked it."Bad Fork Stops"I had tank cream installed when I had the tank done several years ago.I only need a spot done the size of a quarter.I thought of getting some of the stuff that the Bultaco guys use inside but I don't know how this would mix with the cream I have already in the tank.Thanks guys!!



Thomas Carmichael


1970 125 Six Day
1976 250 Hare Scrambler

[Rain Man]

Tom I stuffed a pet cock into my six day tank.  I removed the pet cock and fitting and patched the 1 inch hole up with fiber glass and fiber glass resin.  I'm missing 1 pet cock now, but the fuel tank dosent leak. fiber glass resign will seal it and its sandable too

Raymond
 Down East Pentons

[DKWRACER]

Vinyl-ester resin, perhaps "uncle Ron" would chime in, he has a friend in Texas who can spin one.
Thanks again,
Tom Brosius

[454MRW]

Coming from a background of Corvette repair, I have had very good luck repairing breaks in some of my Penton tanks by grinding the broken areas at least 1/2" past any cracks and laying fiberlass mat (the kind you can get at Walmart) which has the strands in a random pattern and dabbing polyester resin into the matting a layer at a time using throw away 1/2" paint brushes. Do not use the mat that has a burlap pattern or it will shown through the paint job eventually. Allow at least a couple days or more for curing and then sand the repair smooth, and for an extra measure of sealing and to fill any imperfections, I coat the repair, or even the entire tank, with clear POR-15, sand then prime and paint. So far no problems. Just my 2 cents. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 250'S

[firstturn]

Listen to Mike....great post.

Ron Carbaugh

[tmc3c]

Thank You Guys!! Happy New Year!!



Thomas Carmichael


1970 125 Six Day
1976 250 Hare Scrambler

[Lew Mayer]

I thought polyester resin wouldn't work on fuel tanks. I thought you needed to use epoxy resin. Straighten me out on this, Guys.

Lew Mayer

[454MRW]

I have never personally seen the inside of the repair areas after years of use, but I have always used polyester resin, which is the same type used on Corvette fiberglass panels until the late 70's. The POR-15 is just a precautionary measure to make sure any unseen pinholes don't seep or cause problems later. POR-15 can also be used as a substitute for the actual resin for an even stronger repair, but it takes a long time to cure when used on any thick application, and I believe that KBS coatings has bought them out. KBS coatings was started by an employee of POR-15 and supposedly has improved their formula according to a good friend of mine in the Corvette business. A friend of mine repaired his Ultra-Lite fuel tank with Polyester resin with good results, but there is no reason not to use an epoxy resin, but do not use a gel type resin, it is not worth the can it comes in for bonding properties or strength. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 250'S

[DKWRACER]

This post intrigues me...Why?
The first lesson, is that we are dealing with gas tanks that are now 30 years old. They have been subjected to a myriad of fuel/oil combinations.
Two repairs (inside/outside) or combinations of both, could certainly enter into the picture.
I am not a chemist, but I have had both success and failures on both sides of the coin.
Is there a penultimate answer in both regards??? Some sealers (Kreme, Caswell) seem to work. Why then do they work, In an earlier post there was talk about preparation (wash with XXX).
I have had failures with Caswell with proper pre-wash techniques, 6 months later, blisters appeared. And ouch, did that hurt!
Still yet undiscovered, is an inside approach. Brother Ron has a friend in Texas who magically does "tank Spinning"
Mike Winter has also posted about his methods using POR 15 as an external topcoat, which is impervious, and seals spider cracks. But what primer does he recommend? epoxy vs laquer thinned...


This post must continue......
Paint a Stary Night.....again
Thanks for Sharing!
Tom Brosius
Mile High Pentons

[454MRW]

Tom,
The POR-15 coating is very hard, much like gel coat, and is hard to sand, but once fully sanded, it can be primed and painted with Lacquer or Enamel paint with equal success. If the inside of the tank is washed several times with lacquer thinner, I don't see why it couldn't be used as a coating on the inside of the tank, but it tends to run if not applied carefully, usually with a brush. If applied with a spray gun, the same POR-15 thinner must be used and the spray gun cleaned frequently or it will set up in the gun and ruin it. I sprayed my 74.5 175 Enduro tank and still had to smooth out the ultra-fine air bubbles in the coating before it set up completely. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 250'S

[hrbay]

the West System resins, use it in my work and it is versatile stuff. Can be used with many types of cloth both glas and carbon, with excellent result.

GC

[DKWRACER]

Mike Winter, looks as tho POR 15 is a plus to repairing outer cracks etc. Could you post a SKU# for the right stuff to buy?
Thanks for posting!
Tom Brosius

[454MRW]

There are a few suppliers for POR-15 still on the web and all only refer to their product as POR-15 and you choose the color and size, there is no SKU specifically for this product. Clear is the best for fiberglass repairs and sealing. I usually buy a quart $ 38.75 and make sure to dip some out into a separate container for use and reseal the can with wax paper between the lid and the can, or you will never get it open again if any drips into the seam. Wear rubber Gloves!!! It will not come off...ever, you have to wear it off. POR-15 requires no hardener, it dries by exposure to air and moisture.
Tom,
after reading your email about info on the web about VE resins, I noted several times it was mentioned that an Epoxy resin could only be painted with an epoxy paint, with no exceptions. Correct me if I am wrong, but that would make it even harder to match vintage colors. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 250'S

[DKWRACER]

Hear is a "really" good ?
Where would you be if you didn't try?

Recently coated an MC5 tank with POR-15 Pelucid. From my first impression , upon attempting to open the can (15 min)...what magic, will present itself with a non-catalist agent!
I prepped my tank in the usual fashion, being carefull not to break past the gel-coat.
As Mike suggested, used a different container for application with a brush. This stuff is kinda thick and does not spread readily, but rather than risking damage to an "old Sharpe", pushed onward.
It does have an oder, but it did not out gas me outta the shop!
Attemping to "tip off" the topcoat, yielded mixed results, so I just let er cure to see what would happen.
After 8 hrs curing, there were a few tip curtains, but I can sand as well as any body.

After day 4, this stuff was harder than any surface I have seen.
I plan to lightly sand with 220 then re-apply another coat. The first topcoat sealed down well, with about 10 % shrinkage..

If you get some, pay attention to what Mike Winter says ...seal the can as best you can (pun)........
But there are other things, that last a long while!

LT

[tlanders]

WOW. You guys are amazing. When I discovered a leak in my tank at the 2003 ISDTRR in Dalton, I got out Mike Lenz's cure all, Shoe Goo, and put a dab of it where the leak was. It costs about $2 at Wal Mart. Eventually the Shoe Goo started to leak after a few months, so I scrapped it off and put on some Seal All from AutoZone, also about $2, it states it resists gasoline. The Seal All is still working. I won't win any Concours D'elegance with my methods, but it keeps me racing.

Teddy