Tank Sealing

Message

back_marker · #1 Post by **back_marker** » Sat Jan 21, 2012 11:23 pm

I have just spent the afternoon removing and stripping the tank from the Falco so that it can be painted (amongst other jobs). With all talk of expanding tanks due to ethanol in fuel it got me wondering, is it worth sealing the inside of the tank whilst it is off the bike and stripped?

I have been looking at this stuff

http://www.hitchcocksmotorcycles.com/ne ... e_Remedies

as it seems to be the only one that not only claims to be suitable for ethanol fuels, but also is suitable for fibreglass/plastic tanks.

Has anyone got any previous experience of tank sealing, and is there anything I should be watching out for? The job itself seems fairly simple, especially since there is such a large opening in the bottom of the tank with the pump assembly removed, making access and inspection easier.

#2 Post by **mangocrazy** » Sun Jan 22, 2012 2:46 pm

This is something that I find very concerning and have also been thinking of myself. Well done for tracking down a suitable product! From what is written on that site I'll probably buy a pack of that stuff and do the Falco and the VFR tanks at some point in the not too distant future.

Sorry; can't give any personal experience in sealing tanks...

D-Rider · #3 Post by **D-Rider** » Sun Jan 22, 2012 3:18 pm

Unlike petrol, ethanol is soluble in water. When the water content of ethanol fuel reaches a critical level the ethanol component and water separate from the petrol, forming what is referred to as an 'ethanol/water phase'.

This water-carrying liquid accumulates in the bottom of the fuel tank, leaving petrol (without the ethanol component) in the upper layer. This 'phase separation' cannot be reversed.

I wonder whether this suggests a way to create ethanol free fuel .... for a suitably approved laboratory with all the facilities, approvals and precautions in place, of course.

Some of that sealer might be a good idea for mine too ... could do with something to shrink the tank first mind you.
Also finding time to do it will be a challenge.

..... and why, when this stuff (the ethanol not the sealant) causes the damage it does, don't we have some comeback on someone

fatboy · #4 Post by **fatboy** » Sun Jan 22, 2012 7:23 pm

MMMM, Is this cause for concern ?
Anyone have any idea of the ethanol content of UK fuel ?
When it became obvious that my legal woes with DVLA were going to be long winded I tried to syphon the ( 2 month old ) fuel out of the Falco tank, the fumes floored me, my mate found this hilarious then he had a go, yes the fumes floored him too.
Not just petrol fumes in there

D-Rider · #5 Post by **D-Rider** » Sun Jan 22, 2012 8:36 pm

fatboy wrote:MMMM, Is this cause for concern ?
Anyone have any idea of the ethanol content of UK fuel ?

I can't guarantee it's the ethanol as I once stood a packet of baby-bio on the tank, but my tank does seem to have grown somewhat - to the point where I couldn't pivot it up as the brackets at the front hit the top yoke. I have modified things a bit to help matters but it's a very tight fit now.

Dalemac · #6 Post by **Dalemac** » Sun Jan 22, 2012 8:45 pm

D-Rider wrote:
fatboy wrote:MMMM, Is this cause for concern ?
Anyone have any idea of the ethanol content of UK fuel ?
I can't guarantee it's the ethanol as I once stood a packet of baby-bio on the tank, but my tank does seem to have grown somewhat - to the point where I couldn't pivot it up as the brackets at the front hit the top yoke. I have modified things a bit to help matters but it's a very tight fit now.

Mine has definately grown in the last 2 years too, Andy. It skims the top yoke as does yours, and i have never had any baby bio anywhere near it.

Dale

back_marker · #7 Post by **back_marker** » Sun Jan 22, 2012 8:53 pm

I find mine is a very tght fit past the top yoke, plus it is difficult to get the tank bolts in. The back also rubs on the bracket when you tilt the tank, making me think that it has expanded slightly.

To be honest I would leave it but for the fact that the tank is off and ready, plus I would be much happier doing it now before I spend money getting it painted and potentially damege it trying to add sealant at a later date.

My thought is that the problem, on our bikes anyway, it not a huge issue at the moment, but I think the ethanol in fuel issue is not going to go away and will probably get worse, not better, as more of the stuff is added to fuel.

I am interested to hear that your bike has a problem though, from what I can gather the consensus seems to be that it is the water being absorbed into the ethaool and not the stuff itself that is causing the problem. And that it is more of a problem on bikes that sit around a lot (like mine), I was of the understanding that yours is used regualrly year round, which should reduce this effect. Then again, it could all just be speculation and utter bollocks. You think we've got it bad, you should hear the Ducati lot shimfing.

Nooj · #8 Post by **Nooj** » Mon Jan 23, 2012 11:01 am

My tank's grown a bit as well.

Means it doesn't fit so well and is harder to get up and down, but.... I can ride for longer* without filling up so often

*Maybe 10 whole minutes!

back_marker · #9 Post by **back_marker** » Mon Jan 23, 2012 5:10 pm

Nooj wrote:My tank's grown a bit as well.

Means it doesn't fit so well and is harder to get up and down, but.... I can ride for longer* without filling up so often

*Maybe 10 whole minutes!

Indeed. Not saying it's necessarily a bad thing at this point in time, just thinking it may be an idea to try and halt the process at this point before I have to strip half the bike before I can lift the tank.

Nooj · #10 Post by **Nooj** » Mon Jan 23, 2012 8:50 pm

Prevention is the best cure

back_marker · #11 Post by **back_marker** » Sun Jan 29, 2012 6:20 pm

Stuff arrived friday so I was going to have a go at doing the tank today but ran out of time.

I did have a good look at the inside of the tank though and it appears that it already has some kind of thick coating on it.

Has anyone else had a look inside, when they have had the pump out for instance? Does the tank come from the manufacturer like this or has someone already had a go at sealing it? I would be interested to hear what other people's look like if possible.

I did try to take photos but they didn't come out very well.

back_marker · #12 Post by **back_marker** » Sun Aug 12, 2012 6:46 pm

Forgot about updating this but was reminded by Kwakerz on another discussion so here goes.

To be honest all I really did was read the instructions on the box. First you need to remove the fuel cap and pump for obvious reasons, and then ensure that the inside of the tank is spotlessly clean. This is made eaasier by the large hole left when the pump assembly is removed. Worth noting here that as I was having the tank refinished I didn't have to worry too much about damaging the paintwork, other wise I recommend wrapping the tank thoroughly with clingfilm or better stretchwrap if you can get hold of it. Since you will be moving the tank around a lot to clean and seal, you don't have to worry about scratches and bumps, also this can be a pretty messy job so you don't want big globs of epoxy all over your paint.

To clean the tank out I first used plenty of washing liquid with hot water to remove the worst before flushing out with plenty of hot water. After leaving it to dry thoroughly I blanked off the filler hole with some acetate (the clear plastic on toy packaging or similar) and black and nasty (duck tape). I found that to make it seal well I needed to fold up some cardboard to pack out the recess above the filler hole and then some big strips of tape accross the top. Then I poured about half a pint of cellulose thinners into the tank and added a handfull of sharp screws. I am not sure the screws are necessary to scratch up the inside as it is fairly rough already but I did it anyway as I don't want the job to fail. The hole for the pump assembly was then selaed in the same way and the whole tank agitated profusely to try and clean and key in all surfaces.

Once again the tank was left to dry thoroughly before carrying on. The instructions on the sealant say that the amount supplied should be enough to seal two fuel tanks however I got the impression they are thinking of traditional style tanks, not modern sportsbike types that have a much greater surface area, so I used the whole lot for a couple of reasons: First because I didn't want to find there wasn't enough and cock it up, and secondly because it would involve measuring and as I have already mentioned this is pretty messy stuff. I resealed the pump assembly hole in the same way, having removed it to allow the tank to dry.

To mix the sealant I used an old plastic measuring jug (prferrably not one you plan on using again) and put the contents of both cans in (around 750ml) before giving it a thorough stir. Being epoxy you have to be fairly prompt once the two components are mixed. I just poured it into the filler hole, taking care to avoid the lip inside and sealed it as before.

The instructions tell you to move the tank around in all directions for a set amount of time and pour off the excess. I opted to just keep moving the tank around until I was happy that it had gelled sufficiently. With hindsight this was probably unnecessary and a thin coating may do the job just as well.

That's pretty much all there is to it, the tank was allowed to cure for a couple of days (when it settled the sealant had started to pool a little in places where I had not removed the excess) and when I checked it had left a nice thick shiny coating over the inside of the tank. I trimmed off any rough edges left around the two holes and that was job done.

They say it needs to be allowed to fully harden, to be honest I can't remember how long as the tank then went to the paint shop so it had weeks to cure.

Being a fuel tank I can only assume that the sealant has done it's job and not started to dissolve or peel off the side, I am planning to remove the filler cap assembly at some point to have a look at it, so will keep you posted. What I can say though is that the tank would not pass the top yoke when I tried to refit it to the bike. In the months since it seems to be much easier so I think that despite the fact that it is now lined with a thick coating of epoxy, the tank has still managed to shrink back a little. In terms of losing capacity, I have noticed a small drop in mileage on a full tank in the very limited use that it has had but the component parts are approx 750ml, and even allowing for a little expansion as it cures, I believe I have only lost around a litre of capacity (some of which is on the upper surface of the tank which will only affect things if you can genuinely brim it).