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View Full Version : Anyone have a band saw to cut a fuel tank?



Irving
06-20-2020, 19:13
I was trying to clean this fuel tank up, but it's just too gunked up inside. My new plan is to flush it with water a few times, then cut it in half (on one side, right under where the strap goes), clean it manually, then weld it back together.

I'm thinking a big, slow, manual band saw will be the ticket, vertical or horizontal, whichever can cut a straight, clean line through the tank for me. Can anyone help me out with this?

And to answer any questions of "why don't you use a different tank?" it's because I don't want to. I'd rather try to restore this one.

https://lh3.googleusercontent.com/pw/ACtC-3c-ufXWr97BRqa3UB4exY_QnmH7nq8KeIwZUayKev_woO7Dnawk-aNK4_rGexRgLt4cIKtdG4gkFsOxBg830nBI7oDXO4R7HUs7fkQ lQ2lLmfsYE_Kwn-Q9h9WyektEML5mhB_WnyJ-rExH0KS2ev3y7Q=w1112-h625-no?authuser=0
https://lh3.googleusercontent.com/pw/ACtC-3dhhFysJY4mAl10GY-NpGEkK0QZndBE-eMrN-5tR4qySuJnETQ8Re7f4W_tcvz37kl-Zb77heVt8nBENgX0KNTOHosUh_u6EBOOcjpffYboRUC_PHz7lC gBtMkUw6jNQ9KjOwzkAE4qF3Y8XPNEcAwNvQ=w1112-h625-no?authuser=0

Erni
06-20-2020, 19:55
Reverse Electrolysis?


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buffalobo
06-20-2020, 19:59
How long?

buffalobo
06-20-2020, 20:04
https://www.harborfreight.com/3-in-High-Speed-Electric-Cut-Off-Tool-63023.html?ccdenc=eyJjb2RlIjoiMzkzODkwOTQiLCJza3Ui OiI2MzAyMyIsImlzIjoiMTcuOTkiLCJwcm9kdWN0X2lk%0D%0A IjoiMTIxMTQifQ%3D%3D%0D%0A&cid=paid_google|||63023&utm_source=google&utm_medium=cpc&utm_campaign=&utm_content=&gclid=EAIaIQobChMI3pGyv-iR6gIVRtbACh2XgQIUEAQYAyABEgKGqPD_BwE

buffalobo
06-20-2020, 20:06
After you weld it back together and get it clean, get a good motorcycle tank coating in it.

buffalobo
06-20-2020, 20:06
Good luck, will develop new skills.

DFBrews
06-20-2020, 20:09
Circular metal cutting saw

bandsaws like you describe except a big vertical don?t like the varied chip load they tend to catch and distort.

Text me I gots one

BushMasterBoy
06-20-2020, 20:34
The proper way to do it, is put some nut and bolts in it and shake it about. Air clean the inside of the tank using compressed air. Then put the liquid tank liner in. The problem with welding it back together, is it will probably explode! I did that once on a boat tank in a marine repair facility. The rust absorbs the hydrocarbons, then expels them when they get warm. This was a 20 gallon tank and it blew up in my face. I was not injured. The tank was destroyed. Video below shows the procedure.


https://www.youtube.com/watch?v=Sf2veir5VHU

gnihcraes
06-20-2020, 21:24
Die grinder with cutoff wheel.

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BushMasterBoy
06-20-2020, 21:29
https://www.youtube.com/watch?v=9DP5l9yYt-g

Irving
06-20-2020, 21:41
The proper way to do it, is put some nut and bolts in it and shake it about. Air clean the inside of the tank using compressed air. Then put the liquid tank liner in. The problem with welding it back together, is it will probably explode! I did that once on a boat tank in a marine repair facility. The rust absorbs the hydrocarbons, then expels them when they get warm. This was a 20 gallon tank and it blew up in my face. I was not injured. The tank was destroyed. Video below shows the procedure.


https://www.youtube.com/watch?v=Sf2veir5VHU

I've been shaking nuts and bolts around inside with fresh gas. The sludge is so thick that you can't even hear the nuts hitting the metal.
Just tonight I decided to start flushing it with water and that seemed to help as now I can see progress and you can actually hear the nuts hitting the walls.

I think before I cut it, I'll try a pressure sprayer, and maybe something like a snake to get areas the nozzle won't reach.

Irving
06-20-2020, 21:43
Circular metal cutting saw

bandsaws like you describe except a big vertical don?t like the varied chip load they tend to catch and distort.

Text me I gots one

I've got one that I need to fix. I was thinking I'd prefer the thinner blade of the band saw, but I could see having issues with the blade deflecting.


Die grinder with cutoff wheel.



I have this as well, but was thinking I'd really mangle up the cut compared to a band saw.

gnihcraes
06-20-2020, 21:45
Masking tape around it for a cut line to follow.

I have a porta band but it wont be large enough to cut more than a 3 inch cutoff wheel would.

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def90
06-20-2020, 21:46
Take it to a radiator repair shop, they will steam it out.

Irving
06-20-2020, 21:54
Hmmm, I really don't want to explode myself. I might look into the steaming clean at a radiator shop. That's not a bad idea.

I see guys using acetone to clean metal before welding all the time. Why is that not an issue? Is it because it is open air and not closed up in a drum? Would leaving the cap and petcock off help?

If I can avoid cutting and rewelding I'll do that. Thanks for the input.

DFBrews
06-20-2020, 21:55
Also if you want to make a new one I have some 6” aluminum pipe and weld on bungs

Irving
06-20-2020, 21:56
Also if you want to make a new one I have some 6” aluminum pipe and weld on bungs

That definitely piques my interest. I'm really just trying to get this tractor running so I can sell it though. While I look forward to a project that allows me to learn to weld aluminum, I don't want it to be this project.

BushMasterBoy
06-20-2020, 22:06
The tank I was working on was full of water. It still exploded. There is no way I will ever, weld, solder, braze etc. on a used fuel tank. It is akin to stuffing a riding mower with tannerite, you are just asking for it...
I have done a few tanks here at home. One was a 1974 Yamaha and it came out fine. The instructions actually say don't remove all the rust. The reason is that the sealer needs a rough surface to adhere properly. Another tank was a 7 HP Wisconsin motor that runs my compressor. Worked great.

I think the only way to safely weld a tank is if you have a special setup with inert gases in an enclosure for safety and robotics. It would totally suck to loose a hand or an eye.


I used this stuff...

https://www.cyclegear.com/accessories/kreem-fuel-tank-liner?gclid=EAIaIQobChMIj5qYs4aS6gIVB7zACh2COAGEEA QYAiABEgKu_fD_BwE&gclsrc=aw.ds

Irving
06-20-2020, 22:26
Thanks, I'll check it out.

newracer
06-20-2020, 23:03
If you need to cut it put soem dry ice and water in it first. The co2 will displace all the oxygen and then you can safely cut it.

Personally I keep trying to clean it out.

I had good luck with this for sealing.

https://www.mikesxs.net/media/catalog/product/cache/b91127e64e0235c8002267b9d7d4ad2a/1/0/1062110-red-kote-the-only-real-fuel-tank-liner-sealer-1.jpg

Irving
06-20-2020, 23:48
Yeah, I'm going to try more cleaning now that I've made some progress.

Great-Kazoo
06-21-2020, 01:20
Yeah, I'm going to try more cleaning now that I've made some progress.

Buy some wd-40 in a gallon can. Pour it i the tank, maybe 1 cup. shake it a few times then let it sit. That gunked up stuff will come loose and pour out. It will take a few to clean it enough to allow some Kreem or other fuel tank liner, to work. It's one of the few things wd-40 actually works on.

buffalobo
06-21-2020, 10:10
Have you looked around for a salvage replacement?

Now you know why I said good luck and you would learn some new skills.

Irving
06-21-2020, 10:23
I looked on eBay, but everything looked like the same condition. After looking at this thing again, the metal is pretty thin. I can't imagine doing that much spot welding would be fun.

buffalobo
06-21-2020, 10:40
Is it the old Gravely?

buffalobo
06-21-2020, 10:42
Find appropriate size aluminum keg and go to town fabbing.

Irving
06-21-2020, 11:15
Yep, the Gravely.

Irving
06-21-2020, 16:27
All right, never mind everyone. Once I broke a chunk of the sludge off the wall, it's all been breaking loose now. Now when I stick a flashlight in the tank I can see mostly metal. and the nuts keep coming out when I dump the water. Before they would just get buried in the mud and stay in there. I think spraying the hose into the bottom opened up a spot and now fluid can get under the sludge layer and is helping. Now I just need to get a new petcock and move on to the next thing. Thanks for the help on this, as usual.

Not_A_Llama
06-22-2020, 11:06
I know you've resolved it, but Chemtool B12 is the Colonel's 11 herbs and spices of polar and non-polar solvents. That shit breaks anything loose.

Irving
07-02-2020, 17:45
Thank you for the help everyone. I've gotten all the crud out of this tank and used the POR-15 metal prep and tank liner. Now it's drying for the recommend 96 hours. I wasn't really documenting, but if I get this Gravely started I can update if anyone is interested.

On a side note, apparently POR-15 stuff is all the rage right now with off-road guys. My neighbor used it to paint his axle a few months ago. This stuff is still bright and shiny, to the point that every time I look at his truck, I think he's got some new leak. Turns out it's just anywhere that he touched up some paint. The paint is black and it looks like an oil spill. Anyway, I had a cross member to weld up, so he let me use what was left in the can. No exaggeration here, the film that hardened over the top was so tough, that I needed a flat blade screw driver AND a hammer to punch through it. It didn't crumble away once I punched a hole either, I had to peel that layer up like the lid of a beer can. This stuff is TOUGH. I recommend their paint, I hope the tank liner is as tough.

Here is the paint when dry on my cross member.
https://lh3.googleusercontent.com/pw/ACtC-3cGpzlSuVYzT1sGNQTK3FIsUzfM6iosdsf_4yhLkd2G0kCRvaw bwpeudfZZrv5cbENH_rQQraZ7R1VdRdeQkXq8fb__w9bSY4m9d VW3pBmIJQGneJKcHkI6pAV7wJ6_f81a0BMVRSxNAHaSM-JaH0sYew=w1112-h625-no?authuser=0
https://lh3.googleusercontent.com/pw/ACtC-3eZtDjizBmrZASARGoxSNa5APpDFaCSJqews8HmDkPJ9FFddtm w2r7ewLJPI-mG2dsaPJ3z4mKbWvt4D4DgI1odVTBr0FMD5KSpS-JPAJy__2XtyA5qSR1WGRnAELqRQcqgzlo5EEnMXht49j27ks7a 0Q=w1112-h625-no?authuser=0

BPTactical
07-02-2020, 18:28
POR15 is good for certain applications but I will tell you, it is absolutely miserable to try and weld through or any other type of metalworking.

Irving
07-02-2020, 18:33
The dried film was so tough in the can, that I would dread ever having to try and remove it to weld. Probably better off with a wood chisel than a flap disc.