Building An Allloy Tank For My TR5mx

[johnu]

So I'm going to build another alloy tank, some of you may remember the one I made for my t500 a few years ago. This one is for my Triumph tr5mx vintage motocrosser. I have the stock tank but it looks mismatched imho, plus I like custom When I made the other tank I did it all with oxy/acetylene now I have a tig set which is going to make it so much easier to tack up.
I have made the pattern for the tank from sytrofoam and I picked up half a sheet of 3003 alloy 0.063" thick so I'm almost ready to get started. I bought a small cheap ($125) english wheel from Home Cheapo and as a lot of the reviews said it is rubbish and unusable due to misalignment of top and bottom rollers totally crap tolerance on moving parts. However for that price it comes with a full set of dies so that in itself is a bargain. I am modifying the frame and getting everything lined up then I'll be ready to start forming!

 

[johnu]

Got my english wheel modified and operational. Did a little test with a small piece of scrap. My first time using an english wheel! This makes things a lot easier.

 

[Rider52]

Practice and watch your finger tips!

 

[johnu]

Got the first side mostly done!

 

[teazer]

Going for a Maico look... That will work.

 

[johnu]

Moving forward with the tank. I am not going for perfection here, more function. Still learning my new tig welder, one thind is for sure it is so much easier tacking with tig than oxy/acetylene. Still may do the final welding with gas though.

 

[johnu]

Done with o/a. Next hurdle is welding in bungs with my limited tig experience.

 

[ncologerojr]

Looking good man. Nice work!

 

[TresCuatros]

Looks neat!
I had no idea Home Depot sold english wheels.
How was the learning curve getting good at it?

 

[johnu]

Looks neat!
I had no idea Home Depot sold english wheels.
How was the learning curve getting good at it?

Thanks. As I said you have to modify the HD English wheel before you actually use it to getting running true but it is worth the $125 for the dies alone. I have done a lot of fab work (never used the English wheel though) so it didn't take me too long to get use to it. It is amazing how quick it starts to shape the material.

 

[johnu]

Well I welded in the bung for the gas cap. I have virtually zero experience with tig and was very nervous about welding the thick bung to the thin tank but it turned out ok considering my newbie status. It definetly is no pro level but I'm happy. I think my experience with oxy/acetylene helps. I thought it was easier welding thick to thin rather than welding thin to thin!

 

[Maritime]

A little flapper wheel.and that will look great

 

[johnu]

Well I am figuring out that you have to have a perfect joint for tig on thin alloy. I decided to tig the tank bottom in and most of it went well but there were areas were I could not get a good flow. I probably should be practicing more before I weld on the tank but I'm impatient This tank won't be perfect but it will be custom!

 

[Tim]

I had a fancy aluminum tank made by Evan Wilcox for my XS650, and the welds on your tank look every bit as good. Mine even had a pinhole leak at one of the mounting bosses welded in to mate with the frame at the front. I just stuck some fuel tank epoxy to it. It was a massive tank, so I never really filled it anyhow.

Might be too late - but did you think about adding a baffle to the interior of the tank? One of mine had it and it was a nice feature to keep fuel from sloshing around more than needed.

 

[johnu]

Thanks Tim! good call on the baffles, I still have a chance to install baffles when I cut out the bottom for the tunnel

 

[johnu]

I cut out the bottom of the tank for the tunnel today so now I can actually get a better idea of how the tank will look on the bike. If I was doing it again I would of made it two inches shorter as it interferes with the oil tank return line, can modify it to accomodate this though.

 

[doc_rot]

My experience with welding a "t" joint on a thin sheet is the aluminum distorts pretty bad, depending on where you tack them it could mess with the smooth curve and it will be very difficult to hammer and dolly that area. Why not use tank foam like racers do?

 

[johnu]

My experience with welding a "t" joint on a thin sheet is the aluminum distorts pretty bad, depending on where you tack them it could mess with the smooth curve and it will be very difficult to hammer and dolly that area. Why not use tank foam like racers do?

Good call on the foam!

 

[John Murray]

Lovely work, very impressed.

 

[teazer]

Exceptional work as always JohnU.

BTW, Yamaha TZ tanks have a large baffle plate but they don't T weld it. The bottom and top are bent at 90 degrees so that all it has a are a few 1/2" lap welds. Easy to do and less distortion, but foam is even easier.