plastic welding

[ETC57]

Hi all,
Has anybody had any experience with welding plastic?
My pressure washer has one of those cheesy plastic two piece gas tanks and the seam has separated about 2" worth, now I can't put more than half a tank of fuel in it or it starts leaking out the side of the tank!
I sure do miss metal gas tanks.

Jerry

[kenne]

(06-22-2014, 10:50 AM)ETC57 Wrote: Hi all,
Has anybody had any experience with welding plastic?
My pressure washer has one of those cheesy plastic two piece gas tanks and the seam has separated about 2" worth, now I can't put more than half a tank of fuel in it or it starts leaking out the side of the tank!
I sure do miss metal gas tanks.

Jerry

We have had the unfortunate experience of needing the same type of repairs , I have a plastic welder that came from Harbor Freight , (turns out they are all about the same until you pay a huge amount for them ).
Anyway they are not very difficult to use and if you are patient , they do a decent job . Get the one with the built in fan , the others don't work at all . Make sure what material ,PVC,Urethan , or whatever rod is needed , they don't mix well . The welder works on super-heated air
I would do the repair for you ,if you want , but freight might make it not worth it .

[Highpower]

I've tried it in the past Jerry and never had any luck getting them to seal 100% afterwards. If I'm just doing a quick fix, I seal them up with an automotive FIPG (form in place gasket) compound that is used for sealing oil pans these days. Otherwise replacement tanks aren't too awfully expensive. It hurts less than the headache I got from trying to weld them.

YMMV.

[kenne]

(06-22-2014, 10:50 AM)ETC57 Wrote: Hi all,
Has anybody had any experience with welding plastic?
My pressure washer has one of those cheesy plastic two piece gas tanks and the seam has separated about 2" worth, now I can't put more than half a tank of fuel in it or it starts leaking out the side of the tank!
I sure do miss metal gas tanks.

Jerry

This is the welder in question , I have used it about 4 times with varying success , I repaired a rear bumper on my wifes caddy with it as they wanted 4500.00 to replace it (including paint) . That one went well , matter of fact only one didn't really do well , that was because I used the wrong filler . Anyway they are about $40.00-$50.00 at Harbor Freight .... Hope this helps , Good Luck !

[ETC57]

(06-22-2014, 02:01 PM)Highpower Wrote: I've tried it in the past Jerry and never had any luck getting them to seal 100% afterwards. If I'm just doing a quick fix, I seal them up with an automotive FIPG (form in place gasket) compound that is used for sealing oil pans these days. Otherwise replacement tanks aren't too awfully expensive. It hurts less than the headache I got from trying to weld them.

YMMV.

Hi Willie,
Yes I've considered the easy way out but thought if i could get some coaching from some one that's been there done that I just might learn something new, trying as it may be!
Jerry

[Highpower]

Nothing wrong with that Jerry. Been there done that.

I'm with you on the plastic fuel tanks though. Especially plastic gas-cans. I hate the things.

[pjf134]

Plastic welding can be done only on some plastics, but had some success on some that don't. Molded plastic tanks are cross linked PE most of the time and can not be welded, so they say, but I have done it. I have a pro welder and works good. I have also used a solder gun to weld plastic and it worked too. The trick is to fuse together without burning thru just like metal welding. I have had success filling with filler rod and add a band around the tank to keep pressure on the seam using some sort of sealer too. Too much heat or not enough is not good, just make it tackey for a good bond and keep pressure on the filler rod at the same time. I use around 10 psi air on my gun and works fine, it's a knac to do it right and takes time to master it. I use to work at a plastic fab shop back in the 80's.
Paul

[ETC57]

Awesome, thank's Paul It already leaks so nothing ventured nothing gained!!
If at first you don't succeed buy $ buy $ again!!

Jerry