truck saddle tank repair

[ryanjones2150]

These repairs always make me nervous. Some guys say nothing to be nervous about, but cmon, that tank is full of fumes!

I drained as much of the diesel out as I could, popped the fuel cap off and stuck an agron hose inside. The old trusty sniff test detected no vapors at the top of the tank and I could feel them coming out the full hole.

I chose to put a large patch on so most of the dent was covered up. I thought it would look better. All I had laying around was 3/16 6061. So I used that with my fancy cardboard aided drafting and 1/8 4943 to zip it up.

Afterwards I plugged the fuel fittings and replaced the cap, took my air hose and gave it a couple short blasts after hosing down the weld seam with soapy water to cheap for pin holes. Air tight!

For a job like this I generally charge a little more than my normal rate, so if anyone is interested in that aspect, I made about $240 on this job that didn’t take all that long to be honest. The customer was happy with that rate and the repair so it worked out for all of us.

[Bls repair]

Very nice

[MMW]

Looks nice. Did you weld up the gash first or just a patch? Done them both ways. Up here I get ones rotted under the straps mostly, steel and aluminum. I've never had an issue welding diesel tanks but the older I get the more I think about the what ifs.

[ryanjones2150]

I just slapped the patch over it. I think I would have rather used 1/8”, but I didn’t have any. Down on the edge where I made the slits to try and conform it to the contour of the tank, the 3/16” aluminum did not comply easily.

I thought about pulling the dent out and fixing the gash, but this was kind of a rush job. The truck was sitting in my customer’s shop waiting for it so he could get back on the road.

[Don52]

Nice job.
.Don

[Chris401]

That is a better patch than I have ever done. I don't see any of my simple braising working on that gash. However when I braise a pin hole the tank is full of water. Same if I am scraping the tank. I fill it with water before cutting it. Can't say I have ever dropped a metal diesel fuel cell from a passenger vehicle. Is that an old 6.2 Chevrolet truck?

[ryanjones2150]

It’s a saddle tank for an 18-wheeler. It’s about 5’ long.

[Chris401]

Ok. Never patched an aluminum tank, those got sent out to folks who could weld. If it was a Freightliner it probably took longer to reinstall than it did for you to patch.

[Oldgrandad]

Nice work Ryan. Yeah I'm one of those guys that says no biggie I'll weld that gas tank up for you no problem. I always purge with argon a while longer than the calculations say I should, but I still hold my breath when I strike the first arc. Haven't heard a big boom yet

[tarry99]

I've welded on many of those aluminum tanks in my travels over the years..........but not before we've steamed and flushed out the inside of that vessel..........Perhaps the argon was a good Idea?.......I became quite gun shy at an early age after watching my Dad and uncle fix a leak in an old D6 Cat metal fuel tank on the farm.....I must have been 10 and watched them remove it & flush it out with soap & water ......My dad and experienced welder was going to braze it with acetylene in the shop........and midway through......KaBoom!.....blew out the windows and turned that tank into a shredded tin can....after everyone checked there body parts and no one was hurt both of them started to laugh.........I never got over it!

[ryanjones2150]

Took about an hour to fix I guess. Longest part was cutting out that potato shaped patch. Like I said, the truck was sitting in the shop waiting for this tank to get back on the road, so I was glad I could help the guy.

I’m pretty glad this tank go boom. That old D6 you were talking about was probably steel too. If this had been a gasoline tank, no way I would’ve done it.

[Oldgrandad]

The first tank I ever repaired was out of a Cessna and very used, with the good high octane stuff, after a nice long purge it welded with no problems. With the tank full of argon the fumes just can't ignite. The guy that brought it to me said no one else would even touch it. There was a welding shop on the central coast here in California around '05' or so. Two guys trying to repair a gasoline tanker. They killed themselves and blew up their shop and a couple other buildings. Welding on fuel tanks should only be done by those with experience and proper know how.