Re: How to deal with fibreglass

[ferret]

I'm planning to build a saltwater fibreglass tank (FOWLR) in summer since my fishes are getting big. I've no problem for the fabrication of the wooden parts, however, I'm seeking for advices and methods how to apply the fibreglass mat, proper way to deal with the seams etc. or any recommended place where I can learn the technique. Thanks in advance!

[zum14]

A lot of what I learned about these tanks I got from monsterfishkeepers its a freshwater site but has a lot of fibreglass tank builds. I have one started but never finished. Im concerned about the coraline buildup on the walls and if I would be able to keep them clean. Let us know how that goes.

[ferret]

Thanks for the reply! I've checked with the monsterfishkeepers a month before and found that I could build my own wooden tank by firbreglass or liquid membrane. I choose the fibreglass since it sounds easier and cheaper to fabricate particularly in consideration of a glass viewing panel at the front.
However, I can't find any details refering to the applying or laying of fibreglass matt the wooden surfaces or how to deal with both the inside and outside corners.

[zum14]

I dont know a lot about it but i picked a bunch up from a guy at my work who builds boats from plywood and epoxy. You wont be using any automotive fibreglass resins. You need an epoxy such as west systems or east systems. They can get pricey at $150 a gallon. Using a light veil like 3 mil i didnt have any trouble getting the material to wrap edges and such. Id use the biggest pieces you can and wrap the piece through the corner and overlap your seams a bit. Using a bondo blade you can wet the peices out with little epoxy. You can feather them out with fillers after. If i ever decide to build my dream tank it will have strips of carbon fibre in the corners and then a thin veil sheeted overtop. The material is only threre to provide a small amount of support and hold some epoxy. The epoxy is the sealer and the strength needs to be built into the frame of the tank.

[zum14]

Heres what I built so far. Its just a base and will have glass sides. Going to be a frag tank eventually.





Theres no folding here, the material sort of settled into the corner.




Trimmed and filled any unfinished or uneven areas.



Pieces laid out



Wetted them out.



Then I trimmed and sanded and did one more coat of epoxy with black coloring in it. Im still trying to find a case of proper ge1200 that doesnt cost an arm and a leg, then Ill build it. Its about 42X42X18 when done hopefully if ever.

[ferret]

Thank you for the information. I'm planning to purchase some of the materials to build a small tank as trial prior to the fabrication of the big one.

[ferret]

Great photos! That's what I need and want to know. That meant the application of resin to fasten the fibreglass matt on the wooden surfaces needed to divide into quite few stages for the whole wooden tank. Do I need to wait for the resin to dry at one side before I can proceed to with the other side for laying the matt?

[zum14]

I never did but probably should have. You need to be careful as the wet mat tends to basically act a little like wet tissue paper only it doesnt tear (if that makes sense) , wrinkles, the weave will open up, end pieces start sticking to you and you peel them like yarn and is a bit frustrating. You will have to make sure theres no sharp edges and may want to feather the edges a bit for a smoother transition. Its probably more work but a smarter way to go in the end. Takes longer to lay the mat but less work with filling later and you dont have to worry about working bubbles out between two pieces of wet mat. I did this over a couple weeks, did the base then cleaned and filled, did the sides, then cleaned and filled then did the final coat. I would do it the safest and best way you can if your going to put hundreds of gallons of water into this in your house. The epoxy will stick to the wood as long as its clean and dry, it soaks in pretty good. Lots of people I have seen build there tanks out of just plywood and use a couple of coats of just epoxy inside to seal. Im not a huge fan of this and like at least a 3 mil layer inside to give the epoxy a little more to hang onto and help out a bit. Like i said im going to do a strip of carbon fibre in the corners only to really beef it up but my middle name is overkill so.... hmm maybe some kevlar e-glass too..... You basically need to build a boat inside out.

[ferret]

Thanks & I'll give it a try.