working with an iron frame

griffithimage · #1 12/05/2007, 01:03 PM

Hi, I was planning a diy plywood tank and have a friend that has offered to make an iron frame. Some portions of the tank will still be plywood, (bottom, back wall etc)
Are there any threads or examples of people working with iron? I'm unclear on how to affix the joints. Is there another cheap surface (other than plywood) I might employ that would be easy to work with and will bond properly with glass? PLastic?

Thanks

JaredWaites · #2 12/05/2007, 02:37 PM

What I did was use angle iron frames and had them welded. Then had glass cut with bulkheads and all for my returns and had them temper the glass, then I used aquarium silicone and used corner clamps to assemble the tank...been holding water for over 6 years...works like a champ.

JaredWaites · #3 12/05/2007, 02:39 PM

Oh BTW, be sure to use a two part epoxy based paint, pool paint or marine based will be fine after it cures. I used white as it looks good

griffithimage · #4 12/06/2007, 08:58 AM

Hi, maybe this is a stupid question, but did you glue up the glass first then place it within the iron frame? Is the iron also siliconed to the glass?

JaredWaites · #5 12/06/2007, 11:12 AM

Yes, the glass was put together with corner clamps, you know so you can make a 90 degree angle? So I used them and then siliconed inside and outside of the glass, and moved to the other end and did the same thing...then you silicone the frames to the glass.

Fiziksgeek · #6 12/07/2007, 07:50 AM

I welded up my frame just a couple weeks ago. The tank frame is 2 x 2 x 1/8 wall The back sides and bottom will be plywood. I drilled and counter sunk about 300 holes. I sanded the steel with an 80 grit flap disc on the angle grinder to clean it up and give it some tooth. Then I put down a layer of thickened epoxy resin, dropped the wood in and put in the screws. Its quite messy, the epoxy squeezes out of the holes and around the edges, but it makes me feel like I have filled all the gaps good and proper.

The tank is 55 x 40 x 28 external dimensions.

griffithimage · #7 12/07/2007, 12:08 PM

thats a nice deep tank, why did you use the screws? could you have used silicone or construction adhesive?

Fiziksgeek · #8 12/07/2007, 12:16 PM

The screws are really just to make sure I get a nice tight fit between the plywood and the steel angle. The plywood itself doesn't necessarily sit nice and flat, it can have some curve or wavyness to it. So the screws pull it in nice and tight and hold it down into the epoxy. It took a couple hours each on a couple of evenings to drill the holes, but thats a lot cheaper than buying enough clamps to ensure good even pressure!!!

griffithimage · #9 12/07/2007, 12:32 PM

I imagine that it was essential to get an exact cut on your plywood-no gaps between the iron and glass or iron and ply.
Did you sit the viewing glass "on top" on the wood bottom and between the sides?

Fiziksgeek · #10 12/07/2007, 12:41 PM

Well, I am not too far along, only have the bottom in permanently at this point. Been a busy couple weeks!

I cut the plywood to have about a 1/8" gap all around. For the bottom, I also make a 2" wide, 1/8" deep rabbit so that the tank bottom will be completely flat, I dont plan to do this on the sides or back. I also eased over the edges and corners a bit so as not to cause interference with the insides corner of the angle iron and of course the welds. I thickened up the epoxy so it was like peanut butter and spread it out on the angle. This should fill any gaps or imperfections. I then went around with a bit more epoxy (not too thick so it can flow) and filled any gaps between the edge of the plywood and the edge of the angle iron.

The epoxy is great for filling gaps. If everything needed to be perfect, I would not have even tried to do this!

Hope it all makes sense!

-Ken