Hi folks, took the fuel tank off my cat 320 today. It has a rust issue and as you know the stuff likes to grow. I have filled it with water and am about to cut its top off, grind out, wash out, dry, and weld top back on along with a re-neck. Any body done this before and got any tips i.e. where is it best to cut so it's easy to reweld, mig or arc? Trying to use the benefit of hindsight without actually having any. Thanks.
My cutting and welding is so ugly that I would never attempt that. Any chance you can find a concrete mixer big enough to rotate that tank? or strap it to a tractor tire and rotate it? Add sand, gravel or broken glass and enough water to slosh around and let it spin.
Thanks Delmer. Here is the offending article. Looking at it now I am thinking I might go thru the side about half way down, cut the top and sides to the base, fold out the tab, grind, wash and dry, fold back tab, reweld. It looks like a new tank neck will not make it in time so may get some body's to help me poke a bar in the old one and bend it to pop the hollow out of the top and re-neck later. Unless somebody has a better plan.
Look at where the baffles are welded that will give a better location to cut it.I have used stick and mig both.
Weve done allot because of getting the algea out of them find the baffel and cut it so you can get to both sides of it as well as the neck and use a cut off blade or reciprocating saw if you want to try using the old piece over again but with your neck messed up i would use new metal. dont know what kind of filler you will use but make sure you have a vent somewhere
A good way to make a new cheap neck, is to weld a short 2" pipe with female thread to your tank. Than buy a cap and fitting for a pick up style service tank, $25. they have a vent built in.
What about taking it to one of the places that dips the tank and lines the inside with epoxy? That is if a place like that is around your area. I know we have one in Louisville , which I know don't help you , but they do fuel tank repairs on old tractors , cars etc. I'm not sure if they could do a tank like this , but it would keep you from having to cut it , only have to replace the filler neck.
Rather than try to cut a hole and weld the piece back in, how about something like this: http://www.seabuilt.com/10plates.php Rick
I've had to weld up the fuel tank on my dump truck, just used my mig and was sure the tanks was vented. Its holding up well 6 months later. as for cleaning it, smashed up beer bottles and strap it to the farm tractor tire...
Don't know about there, but "here", every transfer/slip tank has a 2 1/2" female in the tank for the lid. And a 2" female for the pump. Andrew
my vote is put some rock's in it and some water or fuel just a couple of gallon's and tumble it or rotate it some how.even if you just hang it from a chain and shake it good and then rotate it to put another side on the bottom until you get all 6 sides it won't take long and it will clean up nice and will be a lot easier than cutting and welding you can probably have it clean before you could get your hole cut in it..don't spin it to fast or the rock's will fall instead of slide across the bottom you want them to slide to scrape the wall's clean
If that had the 7X7700 three tab fuel cap with the lever and padlock loop, you can buy the steel weld ring from CAT, part# 9X2206 or a 4" threaded aluminum ring 9X2207 part numbers may supersede, my notes are ten years old but I know they're still available. Something to consider, both CAT and Deere had a liquid for treating rust, one application turned it into a hard black dang near impenetrable black oxide. Couple quarts of that in a dry tank, let it set overnight, turn it until all six flat sides have been treated, probably outlast all of us? YMMV, I have not tried this myself!
I am unsure of your welding skills, but anytime I need inside a tank, I cut out the size square/circle I need, then after I am complete inside, I take a 1/4 or smaller plate and make it larger than what I cut out and just weld it all around. Have never had any trouble with it leaking. Cheap and quick. You could do that with the neck, fab a plate with the new neck, then cut out from your tank. As far as welding on or in a tank, all you need to do is displace the air inside the tank. I have ran the exhaust off a machine into the tank while welding. Or water works well too.
Once you get the tank cleaned www.eastwood.com has a kit for putting a rust preventing epoxy type coating on it to prevent a reoccurrence.
Thank You for all the replies there are some great ideas right there. I'm really left very impressed by this response. When I got the tank open I was horrified at the state of the interior. The elbow for the fuel supply to the engine was bunged up hence the trickling fuel and periodic starving issues the machine was having. I was tempted to go the rotary abrasion route without cutting the tank open but really wanted to start the year off with a clean tank and be sure every corner of it was cleaned out. Ground most of the rust off with my trusty 5 inch Makita and sandblasted the corners and deeper pits. Will post pix of the sparkling interior tomorrow .