Repair Melt Hole in a Plastic Tank

[kdx Geoff]

Hi,

Can an exhaust melt hole in the bottom of a plastic tank be effectively repaired so the is no future issues with fuel leaks ?

Thanks

Geoff

[FourstrokeForever]

It can be done Geoff but if it's a 2st tank it can be tricky because of the oil residue left in the tank, in which case, you need to thoroughly clean, rinse, clean, rinse until you're happy it's clean. Thoroughly wash the outside of the tank with hot soapy dishwash detergent or similar as well. Basically, the cleaner everything is, the better chance you have of success.
How big is the hole?

[kdx Geoff]

The tanks in the mail. It has a melted area at the right rear and l don't have any experience with melted tanks. l don't like the look of it and want to make sure the tank has maintained its integrity by repairing it or getting it repaired.

[80-85 husky]

ive heard people successfully fix this with a soldering iron but ive only seen disasters with my eyes...

a tricky one and the cleaning issue is probably the main problem. maybe some panel beaters have experience of this with all the plastics on cars now?

You've stacked up the problem jobs allright

[oldfart]

Most Motorcycle plastics were moulded with a lot of wax content ( makes them flexible ) .... the trick is not getting  it too hot so the wax comes to the surface ( puddle ) as it will crack again.
Most bumper repair shops will take thin slivers- from an other area of the part to make repairs  ie  using the same material rather than dissimilar..... different wax contents.

 

[FourstrokeForever]

Most Motorcycle plastics were moulded with a lot of wax content ( makes them flexible ) .... the trick is not getting  it too hot so the wax comes to the surface ( puddle ) as it will crack again.
Most bumper repair shops will take thin slivers- from an other area of the part to make repairs  ie  using the same material rather than dissimilar..... different wax contents.

 

This was my next suggestion if the hole isn't too big. You need similar material to weld up the hole. I have had success with a soldering iron and material slivers from another part of the tank. There is usually a seam along the bottom of the tank to gather the slivers from.
The trick is to heat a small area of the tank and add material by melting it to the heated area as you go along. Take your time as trying to do it all at once will result in failure.

[kdx 175]

i have a rooted kdx tank if you want sum plastic

[evo550]

I had the same problem with an old Maico tank, tried a number of different ways but to no avail (but I'm no expert)
The biggest problem was the flex in the tank which caused the plastic to crack at the join each time.
I also found that the plastic that was "melted" into the hole would set a lot harder than the original plastic around it which didn't aid flexibility.
After about two years of flocking around, I bit the bullet and had a Ali tank made, problem solved.

[FourstrokeForever]

I had the same problem with an old Maico tank, tried a number of different ways but to no avail (but I'm no expert)
The biggest problem was the flex in the tank which caused the plastic to crack at the join each time.
I also found that the plastic that was "melted" into the hole would set a lot harder than the original plastic around it which didn't aid flexibility.
After about two years of flocking around, I bit the bullet and had a Ali tank made, problem solved.

It is a tricky job alright, especially with 2st tanks because the oil residue can actually penetrate into the plastic, particularly at the bottom of the tank. The trick is to not allow the area to get too hot all at once. Think of it like welding thin metal. A little tack to start at several points along the weld. Then start welding a little at a time so the material doesn't get hot enough to blow holes into it. With the plastic, once you have welded a little spot to hold the repair piece in place, then you hold the soldering iron on the fill piece until it melts into the original material. Again, a little at a time. Probably wait around 5 minutes between each weld spot to let the previous area cool down and bond.

[kdx Geoff]

Thanks for everyone's input, l was hoping that there were people out there that professionally repaired damaged tanks but doesn't appear to be the case.

Hopefully the exhaust melt damage on this tank will be superficial 

[Speed]

 Hi Geoff, if you have some donor material.  I have used a product that I can't remember the name of, from NOVATIO AUST PTY LTD.  They have a couple of different products for different types of plastic tanks.  And that work great, they come with some kind of mesh that melts into the base material and bonds.  Contact person is Adrian Gore 0488 553 302
They are at,
7 Dilop Dr Epping VIC 3076

Or, if you don't want to have a go at it your self. Drop me a note and I can probably help you out as I have a friend
also in Epping Vic that still has some of the product and may do the job for you.

Cheers Shane.

[kdx Geoff]

Thanks Shane, l spoke to the local plastic bumper and trim bloke this morning about it and he does the occasional plastic fuel tank repair for cracks. I'll take it to him when it arrives and see what he thinks. If its weak but not leaking he can weld a patch over the area and weld it first if it is leaking

[FourstrokeForever]

Thanks Shane, l spoke to the local plastic bumper and trim bloke this morning about it and he does the occasional plastic fuel tank repair for cracks. I'll take it to him when it arrives and see what he thinks. If its weak but not leaking he can weld a patch over the area and weld it first if it is leaking

Seems like the go if you're not confident in taking it on yourself Geoff. Let us know how you go with the bumper guy as I'm sure there will be plenty of others wanting his service.

[Speed]

Thanks Shane, l spoke to the local plastic bumper and trim bloke this morning about it and he does the occasional plastic fuel tank repair for cracks. I'll take it to him when it arrives and see what he thinks. If its weak but not leaking he can weld a patch over the area and weld it first if it is leaking

Seems like the go if you're not confident in taking it on yourself Geoff. Let us know how you go with the bumper guy as I'm sure there will be plenty of others wanting his service.

That's great Geoff, sounds promising.  One of the products I couldn't remember the name of the other day is called MEGAPLAST PPE. 
http://www.novatio.be/en/product/megaplast-ppe

I still can't remember the name of the other one but they were both from the same company.  One is for hard plastic tanks like the white ones found on some mowers, chainsaws, brush-cutters and the likes and the other is for the waxy plastics like your fuel tank.  Good luck with it and if your plastic bumper guy works out ok. I'm sure there would be plenty of people wanting tanks done.  Cheers.

[kdx Geoff]

The tank arrived and l filed away all the melted crud.....



Its quite firm and I'll make sure the exhaust has clearance when l refit it.

Thanks for everyone's input