450g-500g (UK) steel framed, ply lined idea?

[waynes world]

Hi all, not been on for ages as i have been trying to sort things out in life and now i am back for line for a new tank at long last. So lets look forward to this as i am near ready to start the build, no where near as big as the last one i planned but this will be a gower.

Well the size of tank is max 108x36x36 inchs high, idea is, i have a load of 1 x 3/8 or 25mmx10mm with a 1mm wall thickness steel. i weld the steel tubes back to back to give 25 x 20 and use these as the whole frame work, bearers being 18 inch apart down the back and sides, then line out with 18mm ply and then 2 or 3 layers of 350g GRP tissue to water proof, i knnow there is other ways to waterproof but i will be happier with GRP. Single window of 16mm glass aswell.

I am thinking of the use of the steel as i have a load i need to use up and dont mind the fab work involved, i need to make use of the new welder i have got recently aswell LOL.

Just after a second opinion on the build idea.

Cheers

wolly

 

[fishnutham]

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[CJH]

Well the size of tank is max 108x36x36 inchs high, idea is, i have a load of 1 x 3/8 or 25mmx10mm with a 1mm wall thickness steel. i weld the steel tubes back to back to give 25 x 20 and use these as the whole frame work, bearers being 18 inch apart down the back and sides, then line out with 18mm ply and then 2 or 3 layers of 350g GRP tissue to water proof, i knnow there is other ways to waterproof but i will be happier with GRP. Single window of 16mm glass aswell.

I am thinking of the use of the steel as i have a load i need to use up and dont mind the fab work involved, i need to make use of the new welder i have got recently aswell LOL.

If you have it I think it's a great idea to use it. And since that size of tubing sounds a bit thin for a stand you might as well use it for the tank framing.

Even if you weld two pieces together I would still have the long dimension of the tubing running perpendicular to the frame walls as that axis will be much stronger, even with the seams welded.

You could also cut down on welding time and instead of welding two pieces together you could just use more of it and space it more closely together. That way you're only welding the ends and not so much along the length. You could use some cutoffs to weld blocking horizontally between your vertical members. But either way is fine.

Since that tubing is pretty thin walled I think glass reinforcement is a good idea. I have a workbench with steel 2x4 tubing that is about 1mm thick and while it's quite sturdy I think I'd want a bit more support.

 

[waynes world]

Gald somebody agrees its a good idea, i worked out i dont have enough to do a full frame with the steel doubled up like i said but if i need more i can get it fro an daft cheap price, i will start and see how i go, Just need to move the caravan now and i can put the canopy roof up over the drive to strat the build.


wish me luck