Plastic Welding/Gas Tanks

[jensen 32000]

Anyone have any firsthand experience with this type of repair for cracked gas tanks? I talked to guy, who claims to be quite experienced (24 yrs), said it could be done, and as strong as original, but the appearance would show it has been repaired. He also said the tanks are made of polyethylene, anyone know if that is true?. They seem to want around $40+ CAD, but seeing how expensive, and hard to find, some tanks are, it might be worth while in some cases. Mike

 

[Lawn Masters]

Polyethylene is to the best of my knowledge plastic, but I'm not positive right now. It sounds worth it to me, especially when some saws the fuel tanks are NLA. I'd simply use JB weld on plastice tanks, its readily available and tough stuff. Nothing I've used yet is better, except for bolting steel in place and welding it.

 

[sedanman]

Everyone who reads your response will suffer the loss of at least 10 IQ points. Jensen 32000 SAID it was plastic. There are as many variations on plastic as there are models of chainsaw. What works to repair one type might not even adhere to another.

 

[Tom Dunlap]

Consider plastic welding in the same group as aluminum and magnesium welding. With a skilled operator it works.

I've seen fenders on ATVs welded, snowmobile hoods, tanks too. There are companies that weld kayaks too. If the weldor knows what plastic is being welded, just like knowing what alloy, they can make a good weld.

For simple cracks, epoxy steel works great. A tip that someone taught me is to drill small holes around the repair area. Moosh the epoxy into the holes to make a mushroom head on the inside. This gives the patch an anchor. Put on a couple of thin layers just like joint compound on sheet rock.

Tom

 

[Stumper]

I assumed that we were talking about Plastic Weld - an adhesve/solvent product for repairing thermoplastics. I have never seen or heard of plastic welding comparable to metal welding. How is it done-since the base material is noncondutive I presume that we are using some soldering iron type gizmo to melt and fuse the plastic?

 

[scottr]

Plastic Welding Kit

Mike , I've seen the plastic welding kits in Harbor Freight catalogs. Just be sure to fill the tank with water before heating.

 

[Tom Dunlap]

Like any welding you need to identify the materials in order to pick the right filler rod. then clean the joint. Getting the base materials and filler rod the same temperature in order to get a good weld is the tricky part. If one of the three parts is too hot or cold the weld will suffer.

Not a bad price:

http://www.arizonatools.com/catalog/browse/3190-3197/detail/8034/

Tom

 

[BigSawMan]

Stumper - Its like a soldering gun, but different. You feed these plastic rods into the side of this round soldering gun like heating tip, and it melts it, and it forms with the other plastic. I suppose you could practice on some other peices as to not mess up a tank.


Neil


Oh, they also have ones that run off a hot air gun

 

[TimberMcPherson]

A good plastic match is very important, a mate of mine repairs bumpers and motorcycle fairings proffessionally (including a few of mine) I would say chainsaw tanks would be differcult as they are pretty thin and made of more rigid plastic than the usual plastic weld applications. I did try welding the tank to one of my echo saws with a proper plastic welder and ballsed it up due to inexperience and not being able to match the plastic.

I could ask my mate about fuel tanks as I attempted to do mine well before meeting him

 

[jensen 32000]

Tank Repair

Thank You, for all your responses, guys! The reason I'm asking is; I still have a near mint, 038 non-clear Magnum tank, that the boys from UPS managed to crack severely during the delivery process. After reading here how good they (UPS), are at paying up, I decided I best not put the saw in their destructive hands a second time. Here is a shot of it: Seems like a waste to not reuse it some how. P.S. Thank to Deerguy for helping me out of this Pinch. Mike