Oil tank repairs... let's see 'em

concours · Jul 18, 2015

it's a had a slight dampness on the nether region for a while now, I recently dove in for a closer look. The crack is small, tight, the liquid penetrant barely produced a red stain, but, periphery crack along the toe of the weld securing the bottom mount lug (pattern failure as described here numerous times)
I know how and can repair it, revise it, strengthen it, improve it, etc., my question is rather, let's see how others did it, and perhaps their cleverer(?) method will be shared (shamelessly ripped off :idea: ) or springboard into the next brainstorm. :mrgreen:

Hobot · Jul 18, 2015

Re: Oil tank repairs... let's se 'em

On Peel I just cleaned bottom boss area for JBW then made a doughnut cushion for tank boss to sit in so bottom of tank supported at height not to strain the top mounts. Not much to see but permanently dampened fixture. What would be more interesting and maybe useful is putting oil temp sender in tidy place. Also consider a sight level tooless drain tube.

JimNH · Jul 18, 2015

Re: Oil tank repairs... let's se 'em

I had a mystery leak that would come and go. I had the timing cover off to replace the cone seal and was just looking it over after servicing it up when I leaned on the oil tank and it started to drip. Ah ha!

Anyway, I drained and removed it, rinsed it out with kero and could just make out where it was getting wet. I bead blasted that area and still couldn't see the crack so just welded that area. Looking in the tank after that revealed the extent of the half moon hairline crack so I completed the repair.

That fixed it and I'm going to replace the top mounts with some better from McMaster Carr. I've seen the posts from those who remove the bottom mount but I'm more inclined to just reinforce it come the off season.

Sorry, no pictures but it was just a simple crack on the periphery of the weld.

JimR · Jul 19, 2015

Re: Oil tank repairs... let's se 'em

Check out the repair by CNW. Removed the bottom mount, welded a plate on and strengthens the upper supports. Several years on seems to be working fine.

bwolfie · Jul 19, 2015

This is what I do, braze reinforce both upper tabs and add a lower plate around the existing mount. I also replace the upper rubber mounts with Harley ones. While I'm at it I also remove and plug the chain oiler pipe and hole. I have done several for forum members with positive feedback.
I don't like the idea of removing the lower mount and hanging all the weight off the upper mounts, makes no sense to me.

kommando · Jul 19, 2015

I tried the plate on the bottom with a hole for the mount welded all round and around the mount but it only lasted 5 years, so the next repair was a full plate plus improved top mounts and a rubber pad only on the bottom.

Fast Eddie · Jul 19, 2015

kommando said:
I tried the plate on the bottom with a hole for the mount welded all round and around the mount but it only lasted 5 years, so the next repair was a full plate plus improved top mounts and a rubber pad only on the bottom.

Which is what Matt at cNw does too...

concours · Jul 19, 2015

kommando said:
I tried the plate on the bottom with a hole for the mount welded all round and around the mount but it only lasted 5 years, so the next repair was a full plate plus improved top mounts and a rubber pad only on the bottom.

How is the tank restrained from swinging out...? The battery box captures it to the inside (nice 1/8" neoprene foam pad already in place), do you (and the CNW retrofit) run a foam block inside the side cover to hold it?

concours · Jul 19, 2015

bwolfie said:
This is what I do, braze reinforce both upper tabs and add a lower plate around the existing mount. I also replace the upper rubber mounts with Harley ones. While I'm at it I also remove and plug the chain oiler pipe and hole. I have done several for forum members with positive feedback.
I don't like the idea of removing the lower mount and hanging all the weight off the upper mounts, makes no sense to me.

Nice brasswork mate. :mrgreen: Great images too!

bwolfie · Jul 20, 2015

Thanks, It was one of the first forms of welding I learned as a kid.
There was a dry spell there for a while but lately I have been doing it a bit more.
It's quite therapeutic when it is all going well. I look around for more to work on when I finish up the current task.

kommando · Jul 20, 2015

concours said:
kommando said:

I tried the plate on the bottom with a hole for the mount welded all round and around the mount but it only lasted 5 years, so the next repair was a full plate plus improved top mounts and a rubber pad only on the bottom.

Click to expand...

How is the tank restrained from swinging out...? The battery box captures it to the inside (nice 1/8" neoprene foam pad already in place), do you (and the CNW retrofit) run a foam block inside the side cover to hold it?

Nothing there, front and back top mounts are 5/16 instead of 1/4 and once tight hold it in place, the bottom pad is only over the plate not the seam and it all seems to work. The cover is located to the top of the tank by 2 bolts and the bottom of the cover has a rubber buffer trapped in the frame so its all tightly held.

wjrich · Jul 20, 2015

bwolfie said:
This is what I do, braze reinforce both upper tabs and add a lower plate around the existing mount. I also replace the upper rubber mounts with Harley ones. While I'm at it I also remove and plug the chain oiler pipe and hole. I have done several for forum members with positive feedback.
I don't like the idea of removing the lower mount and hanging all the weight off the upper mounts, makes no sense to me.

Did a nice job on my oil tank...

swooshdave · Jul 20, 2015

I have the bigger top mounts, no bottom mount and industrial Velcro that holds the tank to the battery box.

kommando · Jul 21, 2015

Second tank ready for the Combat.

concours · Jul 21, 2015

What rubber on the bottom? Closed cell neoprene? 1/2" T? Old car tire sidewall ala hobot?

concours · Jul 23, 2015

Repairs went well, but... the seam weld has a small leak... up high. The gift that keeps giving... it had been there it’s whole life. Prolly just some mist/drool.

kommando · Jul 24, 2015

I used this pad and cut it to the shape of the flat bottom and glued it on with superglue as the paint was fresh. Thickness is about 5mm.

Hobot · Jul 24, 2015

I had to cut a hole in my pad to clear the unused bottom cracking leaking bolt mount boss. I did consider the type of pad material so not to crush down over time and heat so main vibe loads begin working on the top mounts fracture or clanking noise. D/t distorted top mounts or luck of the draw on both Peel and Trixie I had to slit a hose over the top seam flange that is jammed pretty tight to frame tube - to take the rough paths with too frequent crashes. I may be only one that constantly has to consider & recovery from crash survival.

Brithit · Jul 24, 2015

I removed the rear tab, after the second time it cracked. I came up with a two piece rear mount that clamps on to the filler neck. I wanted to include a picture of this, but it just doesn't show up in a photo very well. Take steel tubing about the same size at the filler neck. Cut off a "ring" of it, approx 1/2" wide. Cut that ring into two halves. Fit them around the neck., and hold them on with a very thin hose clamp. I used one off of a BMW fork gaiter. Probably not much wider than 1/4", but fairly strong. You'll have to do a little grinding on the rings to get them to mount low on the tank. When you place them on the tank, you'll see what I mean. Once I had that in place, I made a bracket that came out to have a mounting hole exactly where the original tab mounted. Brazed that on to the rear half ring. So the whole thing clamps on to the tank - three parts - two halves of the ring, one with the tab attached to it - and the clamp. I've done two of these, and they have both held up very well. I even got a nod from a very well renowned British wrench when he saw it.

concours · Jul 27, 2015

All great stuff! Thanks!
The leak on the top seam, it occurs to me is possibly a product of the sketchy seam weld up near the baffle hump, and edge welded to try and repair it.

I'll need to get down to the pinch weld to seal the leak path.