Repairing plastic fuel tank, what glue/materials?

[Tsiklonaut]

Having plans repairing 41 litre TT tank off from the wrecked bike. It has 1 bigger hole and cracked foot that fixes the tank on the bike. It looks repairable.

Anyone knows are there some good glues/materials to fix it so it'll be vibration resistant and well sealed?

Thanks'n'advance, Margus

 

[RickG]

Depends on what sort of plastic the tank is made from. You need to figure this out first and then find an adhesive that is compatible with both the tank (meaning it sticks to it like stuff to a blanket) and is 100% petrol proof. A reinforced (fibreglass) epoxy is possibly the way to go but there are many types and formulations.

Check out the manufacturers below and go through their technical data to find a likely candidate; call them if necessary, they are usually helpful and will also give the name of your local supplier:

www.loctite.com

and

www.huntsman.com (they make araldite)

 

[Gaz]

contact Muppet on this site for info, he used to have a business that did plastic repairs on bikes, he's done all the training and knows his stuff.

 

[(RIP) Kaister]

loctite 9394 should do it - if you can get it and afford it.

 

[Tsiklonaut]

Thanks mates!

loctite 9394 should do it - if you can get it and afford it.

Found on eBay: 50 millilitres, 20$ i think i need lot of that, 5 tubes or so

 

[madman]

Bostik M890 is what we used to use on aircraft fuel tanks. You can slap a patch on with the stuff even if the fuel is still pouring out! Works with plastics and metal if my memory serves me.

Bob
http://bikesindordogne.blogspot.com/

 

[mumfy]

Having plans repairing 41 litre TT tank off from the wrecked bike. It has 1 bigger hole and cracked foot that fixes the tank on the bike. It looks repairable.

Anyone knows are there some good glues/materials to fix it so it'll be vibration resistant and well sealed?

Thanks'n'advance, Margus

try BUSTERS thay do stuff that is bril for plastic repairs small pack is £10 i cannot rember the name but i have used it and it works well

 

[Muppet]

Margus, have you thought about getting it professionally welded? If it's of a weldable plastic I'd have thought this would be your best long term solution, with perhaps a glued patch over the area for double security.

You need to look for some writing on the tank in raised lettering. It will have some arrows pointing inwards to a code which indicates the plastic type. Like this:

> ABS <

Or:

> PA< or > PP/PE <

The lettering tells you what the plastic type is, and this identifies whether it can be welded or not. You need to have a proper welding gun and the correct welding rods to do this properly, PM me for more specific advice if you want it. If I was asked to do this sort of repair when I fixed bikes it would have cost about £40 for an unpainted repair.

 

[Tsiklonaut]

Thanks for the essential info!

I can't find any marking on the tank tho, other than BMW

It's a Touratech, the older model. On TT web page it's made from polyamide, altough i've read on ADVrider where someone sayed the older model of the tank was acctually from some other plastic and actually better.

Any idea which companies identifies the plastic type and repairs such stuff?

Maybe worth checking the yacht-marine etc factories or service companies, coz boats etc have frames and etc made from plastic as well and they sometimes need repairing and sealing(?)

Margus, have you thought about getting it professionally welded? If it's of a weldable plastic I'd have thought this would be your best long term solution, with perhaps a glued patch over the area for double security.

You need to look for some writing on the tank in raised lettering. It will have some arrows pointing inwards to a code which indicates the plastic type. Like this:

> ABS <

Or:

> PA< or > PP/PE <

The lettering tells you what the plastic type is, and this identifies whether it can be welded or not. You need to have a proper welding gun and the correct welding rods to do this properly, PM me for more specific advice if you want it. If I was asked to do this sort of repair when I fixed bikes it would have cost about £40 for an unpainted repair.

 

[Tsiklonaut]

The tank is broken on two spots arrowed on the pic:

This is the most critical part - the tank's foot is broken off. Foot itself is from metal and i have it. The foot's hole is firm and looks it can be glued back into it easily.

But the crack from the hole extends few inches.

This is the other broken part, it's the sharp edge of the tank under the seat, this looks like piece of cake to repair coz it's not a critical spot, i'd just fill it with glue or repair material.

 

[(RIP) Kaister]

That looks very much like fibreglass to me.

If it is its farily easily repairable by a boatyard or a decet bodyshop

 

[Muppet]

Yup,

I'd say the same, fibreglass, unless someone's done s previous repair using glass mat and resin?

Take it into a boat builders to see what they say, if it is fibreglass you can probably do it yourself.

 

[Tsiklonaut]

Danko guys!

Just had a call with the boat repair guys. They do it with Epoxy, and say should be relatively vibration resistant too. Any idea which one would be the best for tank use?

 

[Tsiklonaut]

Fixed

By the guy who builds canoes and (waterflow massage) baths . The same materials/glues they're using for canoes etc boats.

Let's see if it holds the fuel in the long term or i'll blow up with the bike. Any idea what type of paint they're using inside the tanks (both metal and plastic tanks are painted from the inside by manufacturer)? It's painted from the inside originally, so i probably have to repaint the fixed spots.

Gonna have it repainted from the outside too, maybe something different - any interesting paint ideas?

 

[Muppet]

Nice job they;ve done too Margus.

Try and find a paint that's petrol resistant (normally a good quality clear lacquer will be sufficient but not practical on the inside of the tank.

Rather than trying to paint it by spraying, if you thin the paint out so it's nice and runny (as if it were going to be sprayed rather than brush painted) you could try 'rolling' it around the inside of the tank to coat it. Doesn't matter if it's thick in some parts, but be careful around the hole where the sender/pump unit bolt onto not to get too much on there and affect the seal.

 

[Tsiklonaut]

mounted

My brother just repainted the bits.

I meself shortened and reshaped the beak too. Looks like this:

Still I have some minor probs left:

1) needs a new proper cap, current weak car cap leaks when full and doing offroad.

2) Fuel pump assembly leaks a bit, it's an old prob started when I was in Iran, just a drop or two petrol per overnight occurs beneth the tank and I know the cause: the fuel pump assembly's contact surface isn't smooth so I need to polish it to reseal it properly.

3) There's a very small additional crack in front of the tank, also has a very minor leak when tanked full. Some small amount of grinding + EPOXY will seal it.

I'm happy so far, looks like the main support's fix works, I've done some hard offroad to test it and looks like it's working to it's peak performance.

Now those 3 minor probs left that need fixing. Can't wait to have 400 miles of fuel stop intervals again on touring and communiting, pure luxury. Compared to stock the strongest point for that 41L tank is the centre of gravity, most of it sits in the height of my knees - it makes the bike so unbelievably nimble in the curves while carring that much of petrol

Cheers, Margus

 

[Tsiklonaut]

Looks like it's still a little leak there, on the newly repaired spots.

And I think I have a theory: the plastic, especially fiberglass "breathes", so the petrol/petrol fumes go between the fibre channels.

Few drops of petrol per overnight stay. Not a secure way to ride the bike still...

Originally there was a black coloured protective layer inside the tank that was partly removed for the spots that needed repair, so I reckon the leak is because of that protective layer removal, so the fiberglass "breathes" on those spots again.

Found an EPOXY-based gas tank specialized sealer: http://www.caswelleurope.co.uk/gastank.htm

Any thoughts on this product?

Couldn't contact them tho., they can't send me e-mail, dunno why and I don't have a FAX. Tried to Google, but couldn't find any other stuff for sale like that.

 

[(RIP) Kaister]

........And I think I have a theory: the plastic, especially fiberglass "breathes", so the petrol/petrol fumes go between the fibre channels.

er...nope...the epoxy resin is the glue between the strands.

GRP - glass reinforced PLASTIC (epoxy)

 

[Leopold Lee]

Looks like it's still a little leak there, on the newly repaired spots.

And I think I have a theory: the plastic, especially fiberglass "breathes", so the petrol/petrol fumes go between the fibre channels.

Few drops of petrol per overnight stay. Not a secure way to ride the bike still...

Originally there was a black coloured protective layer inside the tank that was partly removed for the spots that needed repair, so I reckon the leak is because of that protective layer removal, so the fiberglass "breathes" on those spots again.

Found an EPOXY-based gas tank specialized sealer: http://www.caswelleurope.co.uk/gastank.htm

Any thoughts on this product?

Couldn't contact them tho., they can't send me e-mail, dunno why and I don't have a FAX. Tried to Google, but couldn't find any other stuff for sale like that.

I bought a used Toutatech tank for r1150gs, but sadly it has cracked just like yours. I searched everywhere but I could not find the fix for it. I know this post was a long time ago, but have you figured it out? The protective layer inside the tank is also gone. I need your help!