Fiberglass tank. What to seal it with?

Status
Not open for further replies.
Joined
Nov 8, 2010
Messages
16
I picked up a fiberglass interstate tank today for my 72. My steal tank is going to take a bit of work to get it back in shape after a bad POR-15 install. The shop i got the FB tank from said I should seal it before i use any ethanol fuel. What are you guys using for this? How long will the ethanol take to hurt the tank?
 
LOL! Tank sealer may be edging out oil threads for repeat confusion.

Caswell sell a 2 part epoxy sealer with very good chemical ethanol resistance, if you can get it to stick and thick enough layer or two. This is what I and many other have done, with only a few failures reported after a couple years from unknown cause but many many more doing just fine last decade or so.

Scroll down the posts a few pages as this subject was recently covered, in several posts, to the maximum effort and expense possible plus lingering mystery to source the ideal materials in less than industrial scale lots. Read up then Your call.
 
Holey Cow, how many times are we going to cover this?

Not trying to be rude.

Avgas LL110 rules.

Dave
69S
 
I have had great success with this 1 part stuff. 1 pint will do 3 or 4 tanks. Steel tanks too. Read up on it.

http://www.hirschauto.com/prodinfo.asp? ... ation=PINT

Condition the inside with a pint of Acetone and removing right away. Dry completely and thoroughly. Tape your petcock hole and wrap the tank with cellophane to protect paint during the hole process. Dump the entire pint in (no need to rush at this point). Tape over the filler hole and tumble and swish and shake and....well you get the idea. Remove tape from one of the petcock and empty the sealant back into the can. Work it around to get as much as you can out cause when you leave it to dry it will pool to some extent so when you have it emptied, keep it moving for as long as you can stay interested.
Remenber, with this stuff it's thin to win. Don't over do it. One coat only.

The threaded hole may have a residue and makes a good sealant for the petcocks.
 
pvisseriii,
how many tanks have you done and how long have they lasted with this stuff?

Dave
69S
 
DogT said:
Holey Cow, how many times are we going to cover this?

Not trying to be rude.

Avgas LL110 rules.

Dave
69S

I did a search, didn't find anything specific. I may pick up a 5 gallons of c-12 and mix it with pump fuel.

Caswell's is what the local guy said he uses too.
 
You can get LL110 avgas at your local airport. No ethanol, no Casewell, no Hirsch, etc., runs good in a Norton. About $4.50 or so per gallon, but if you don't run all over the country you can get a good days driving out of a roadster tank, at least for me at my age of 67. Don't have to worry about gum in the carbs.

Do what you have to.

Dave
69S
 
Thin to win eh. hm. Best wishes.
Caswell sealer kit is rather thick to start with and after slowly drooling out the excess, two cigarretts worth of turning by hand, with more hesitation in trouble spots, it becomes set enough to stay put w/o pooling leaving ~1/8" thick protector.
I and my buddy Wes only did one good thick layer, other says do 2 or 3. I know Caswell is tough enough to make a whole tank out of and has saved my IS tank in a front crush event. Thick tough compliant coverage is my preference.

Both me and Wes used a good wash of acetone for a few minutes, 10, first to clean grime and then dry definitively by forced hot air a day or more.
 
None of the untested snake oil tank "sealers" are likely to work long term, but there are proper industrial products which would seem to me to work just fine. Search ITW web pages for details of appropriate materials, and remember that once a snake oil fails a tank is then usually scrap.
 
"Snake oil"? I don't think any of the sealer company's are trying to mislead. Most of the products on the market were around before the crap fuel we have now.

What is this ITW you speak of? Do you know of the appropriate materials I should be searching for? Or should I just take a shot in the dark?
 
Main reason the snake oils are rather unlikely to work long term in a GRP tank, is primarily due to the fact that most are very brittle when cured, which means when they are used as a slosh coat that cracking is certainly a very strong possibility.

Add to this the fact that ultimate chemical resistance level relies very heavily on the temperature of the cure and post cure processes, and you then have a couple of very good reasons to regard the snake oils as nothing more than a temporary fix.

If those selling these products had any sort of faith in the fact they were able to provide a long term cure for problem fuel tanks, then there seems little reason not to have had the products properly tested, in controlled lab conditions, as well as carefully monitored real world tests using E85 as a control fuel.

Novalac vinyl ester filled industrial sealing products seem like they might be ideal for sealing tanks, as they are less brittle than epoxies, and the fill material means they are far more durable and able to resist cracking from vibration far more effectively than epoxy products.
 
DogT said:
pvisseriii,
how many tanks have you done and how long have they lasted with this stuff?

Dave
69S
Two, 1 fiberglass and 1 steel.
As well as this stuff has worked for me, I CANNOT believe nobody else has a comment on it. I don't want to line a tank, I want to seal it from ethanol, however the sealing properties is great for a good used steel tank to guard against pin holes and the like.
Let make this clear, this is not an applied liner that comes floating to the surface next year. And another thing, i feel that most of the systems will work just fine if proper procedures are followed to the letter and add another level of precaution. Too many wannbe's take the short cut to success and report the bad results. Know when something is over your head before blaming other for your incompetance.

Dave, this is a general statement and NOT directed at you in any way or anyone else that i can think of at this particular moment. :) :D :lol:
 
Fill it with concrete and use it as a boat anchor. Then find a good steel tank for your Norton.
 
pvisseriii,
I agree, it is probably all in the prep. I just haven't decided to take the plunge as long as I can use Avgas. A tank of gas is about all I can handle riding at my age. I do think Carbonfibre has a point though, none of the products have been thoroughly tested by any scientific method.

How long have your tanks been in use? Do you drain them often or leave fuel in them all winter? I even drain the avgas.

Dave
 
cycletech said:
maylar said:
Fill it with concrete and use it as a boat anchor. Then find a good steel tank for your Norton.

Wow! That's really helpful. Now GFY.

I wasn't trying to be a jerk...

The subject of fiberglass tank sealing has been beaten to death here. There is no sealer that has proven to be effective for more than a couple of years. Steel (or alloy) is the only long term solution. Sorry if that's not what you wanted to hear.
 
maylar said:
Fill it with concrete and use it as a boat anchor. Then find a good steel tank for your Norton.

Since it has no fluke it would probably be a poor anchor, but you've got the right idea.
 
DogT said:
pvisseriii,
I agree, it is probably all in the prep. I just haven't decided to take the plunge as long as I can use Avgas. A tank of gas is about all I can handle riding at my age. I do think Carbonfibre has a point though, none of the products have been thoroughly tested by any scientific method.

How long have your tanks been in use? Do you drain them often or leave fuel in them all winter? I even drain the avgas.

Dave

The type of sealing products used industrially, seem to be perfect for sealing a GRP tank. Main reason these are not easily available is to do with cost, and the fact that the snake oilers would be unable to make the 400-500% profits that are currently the norm.

Seems a real shame that the greed of these people, in effect means that there isnt much chance of effective products coming on the market, and that in 2 out of 3 cases a sealed GRP tank is likely to become scrap at some stage after its been "sealed"!
 
DogT said:
pvisseriii,
I agree, it is probably all in the prep. I just haven't decided to take the plunge as long as I can use Avgas. A tank of gas is about all I can handle riding at my age. I do think Carbonfibre has a point though, none of the products have been thoroughly tested by any scientific method.

How long have your tanks been in use? Do you drain them often or leave fuel in them all winter? I even drain the avgas.

Dave
I never store anything with gas left in it. Lawnmower, weedeater, snowblower, motorcycle, drain and run it out of gas.
3 years on the glass tank. Steel is fresh.
 
Status
Not open for further replies.
Back
Top