Friday, February 17, 2017

Gas tank welding

Went for a ride on Saturday and discovered that the repair I'd made to my '91 Jag's gas tank filler neck was insufficient. It leaked gas on my left foot the whole ride. Relatively safe, the exhaust is on the other side ;)

Anyway today I finally had a chance to attack the problem. I got a Harbor Freight plastic welding iron and began by cleaning the crack with the included wire brush. Then I repeatedly stabbed the iron into the plastic perpendicular to the crack. My idea here was to essentially stitch the crack back together:

That worked pretty well and when I was done I could no longer see a strong flashlight shining through the crack.

Then I took some of the filler material that comes with the iron and worked it into the repair. I'm hoping it'll add some strength. Fortunately theres a groove there anyway. Here I'm partway done:

I ran the filler material over all of the damaged part. I left the undamaged section alone, I may live to regret that...

Tested by putting in a few gallons of water, holding my hand over the filler hole and flipping the tank upside down. If I can manage to not screw it up during install it should be okay:

Right now its got a quart of denatured alcohol (all I had on hand) in it to absorb the water. I'll get more alcohol later today.

As a measure of safety I rinsed the tank with water yesterday. I'd tried to have the filler neck full of frozen water but couldn't get the water to stay in long enough to freeze. I did all the work outside, there was a good breeze and the ambient temp was below freezing. I wore a full face mask and had an extinguisher nearby. I sat in the middle of the driveway away from anything flammable and of course had lots of snow on hand.

Overall I consider this a success, I didn't get blowed up, in fact I never felt like I was really in any danger, no sizzling or fire of any kind...