Sealing a fiberglass tank.

Peashooter · Jun 25, 2010

I'm new to this forum, so please excuse me if this subject has been covered. I have a '73 Commando that has set since 1979. Mechanicaly I am good, but the tank is rusted out. I purchused a NOS fiberglass tank on ebay ( never had gas in it) and I've heard that it would be a good idea seal it before use. Hope to start riding her this summer ( have a '66 Atlas I'm riding now) and I'm ready for the tank.

mike996 · Jun 25, 2010

Caswell is what you want: http://www.caswellplating.com/aids/epoxygas.htm

Jeandr · Jun 25, 2010

I used Hirsch sealer http://www.hirschauto.com/ There are a few threads on this very subject gas-tank-sealer-t4653.html?hilit=%20sealer and fixing-fiberglass-tank-t6227.html?hilit=%20fiberglass

Jean

Peashooter · Jun 25, 2010

Have any of you all used Caswell yourselfs in a fiberglass tank? I just want to get it right the first time. I have fought improperly applied Cream in steel tanks before, and it's a mess.

JimC · Jun 25, 2010

Judging from the posts here I'd say the sealing of fiberglass tanks results are mixed, at best. I made the switch from glass to aluminum. Waldridge had some aluminum Roadster tanks, with Monza cap, for $395. They are not suitable for polishing, but with some work they can be painted.

mikegray660 · Jun 26, 2010

Peashooter said:
Have any of you all used Caswell yourselfs in a fiberglass tank? I just want to get it right the first time. I have fought improperly applied Cream in steel tanks before, and it's a mess.

yes - the only way to get a good sealing job is to do it twice - follow all the instructions to the letter on the first coat then real seal again after the first coat was hardened.

that being said, after doing 4-5 tanks with the caswell and having them all eventually leak (some took 2-3 years, but they did)- i have sworn off the fiberglass tanks and gone to alloy ones. The problem if that no matter what, the ethanol in the gas will eventually find its way through and eat a hole in the tank and RUIN your paint job. I once had the small leak become a flood while on a moderately long trip, and only lots of JB weld and sand-paper got me home.

In additon the melting glass has to go somewhere - and thats our cylinder head where it will coat your intakes and your valves and can eventually cause damage to them

- if you have "real" gas in your neck of the woods maybe you'd fair off a bit better.

if your tight - caswell the tank and don't get a good paint job - but plan on replacing it when the $ is there
otherwise get a good steel /alloy tank and forget about it
m

bchessell · Jun 26, 2010

I sealed my 68 fastback tank with caswell as well as buying a bartell aluminum tank from walridge.I run shell gas up here in canada which I am told does not have any ethelol.My aluminum tank is on a 71 fastback I just completed. I only run shell which is at our corner in the 68.If I am only running it once in awhile I drain it. I have seen first hand what ethenol can do and almost lost a fresh engine because of it on a fastback I restored and sold.There are steel and aluminum tanks out there now and if it your only commando I would try and get one no matter what the cost. If you have more than one commando roadster just paint them the same and use the new tank on either as I do on my fastbacks.As the last post said the ethenol will cause the tank to fail sooner or later.
My 68 is original and that is the only reason I keep it that way.
Bruce

mike996 · Jun 26, 2010

I agree with the ldea of using only a metal tank but I could not find a metal fastback tank so I purchased a new FG one from Burton's Bike Bits in the UK. THey told me the tanks were constructed with resin that was not affected by ethanol but recommended it be sealed anyway. I did that with Caswells before any fuel was put in the tank.

I do know from experience with FG marine gas tanks in Hatteras brand boats (all their boats, gas and diesel, had FG tanks which, at the time was considered the best tank available - much better and longer lasting than steel/or AL. But in the early 80's they identified problems with ethanol so they changed the resin to an ethanol resistant type and those tanks are not considered to have a problem with ethanol. So it DOES appear that an FG tank can be made with a resin that will not react badly. THe question is whether any particular tank was made that way.

bchessell · Jun 26, 2010

My bartell is an aluminum fastback tank.
Bruce

prmurat · Jun 27, 2010

JimC: where did you find your alloy tank at such a good price: Walridge offersthis:
Roadster style. 06-2026A $638.75

Philippe

rvich · Jun 27, 2010

prmurat said:
JimC: where did you find your alloy tank at such a good price: Walridge offersthis:
Roadster style. 06-2026A $638.75

Philippe

Call them...they might be gone.

hobot · Jun 27, 2010

Me and my Cdo buddy Westley, have both had good success with
2 part Caswell sealer in FG Hi Ryder and IS tanks for over 6 years.
His has never been left w/o gas in it and mine for 3 year before
emptied to repaint from crashes the shattered the weave by front
crush yet did not break sealer sealing.

I do believe one could make a whole tank out of just the epoxy.
Might have to take your sweet time by continuous rolling to form
a thick intact layer, like 30 min before pouring cold honey like
excess out then about 45 min more changing position so
it don't sag off the high and low spots.
Heating tank in sun or hair drier also speeds set up.
I used wooden dowels carefully self tapped into fuel taps
to extend a bit beyond-proud inside to keep threads and
drain clear. I lightly greased dowel and used them
twice now, on for FG IS tank and for steel rusting Roadster.
One quart size order did them both and still some left
over for what ever.

hobot

mike996 · Jun 27, 2010

"My bartell is an aluminum fastback tank."

I have never heard that name and don't find any listing for such using a google search for Bartell related to AL motorcycle tanks. Where does one obtain one of these tanks? HOw much do they cost? Does it actually bolt in place and fit the oem fastback seat?

bchessell · Jun 27, 2010

I bought mine 3 years ago.Walridge can get them and they come with a brushed finish for painting.I sanded and buffed mine to a shine .They are pricey and hold 4 Canadian gallons. I have gone 180 miles and not hit reserve. Send me an e mail and I will send you some pics.
Bruce bchessell@odyssey.on.ca