Backyard Aquaponics
A place to discuss aquaponics

Has anyone tried their hands at making a fiberglass tank? Can they be made to be food safe/food grade? I know Murry sells fiberglass tanks but i would like it build my own.

Stucco also does fiberglass.

I think the key to making it food safe/food grade is the coating. Some form of food safe marine grade gel coat.

When i looked into it wasn't very cost effective unless you can get commercial supply prices fro FBglass

We done it at school on the Energy Breakthough bikes... Not very nice stuff to play with.... But just imagine the possibilities if you got it going

fish powered fiberglass bike

Fibreglass products are very expensive for amateurs to buy.

If buying fibreglass products be carefull to ensure they are well made. This is not always easy to tell until too late. My beds and my rectangular tank have large areas of air exclusions under the gelcoat, particularly in the non flat areas such as the internal corners. As a result, the gelcoat has not support and simply cracks under pressure. I assume this occurs when the chopper gun spraying of fibregalss and resin onto the mould is not done properly. If the fibregalss was laid up by hand - as an amateur would do or a professional would do in more critical applications I guess, this would be less likely to happen.

When I find the time, I will launch into a repair of my fibreglass AP products, some of which I have never used. When I do this I will take some pictures of the project and post for interest of readers. Luckily I have dabbled with fibreglassing a couple of times in the last couple of years when doing work on my canoe and some other hobby jobs, so I am not entirely green at this (no pun intended - for those who know a bit about fibreglassing ).

This is certainly true for pre-made items such as FTs and STs. However if you are constructing a permanent system of a reasonable size, then it certainly offers a decent ROI.
The only issue is that it does take a bit a leap to be able to attempt this. Buying on the small scale makes it somewhat expensive. You have the cost of the fibre glass roll. As well as the agent and hardener as well as the gel coat. Also there is the matter of the brushes or rollers, gloves, masks, mixing trays and time/costs wasted when the batch you have just mixed goes off too early before you have managed to get it all set. (Yeah, the voice of experience).

On the whole, I prefer a home made fibre glass setup. For one you don't have to worry too much about leaks as in general they are stronger and more resilient to punctures. The actual construction of the item is more geared to the actual layout suitable for your area. You are not limited to standard sized tanks or spaces. FG setups generally last longer than liners (UV degradation, putting a hole in the liner etc.). They are easy to repair (drain to expose crack, mix a new batch and apply).

The only drawbacks are costs. In my experience, the convenience of the layout more than makes up for the additional costs. And that cost is not very much in monetary terms. Where the biggest cost lies is in time. A fibre glass construction is not the sort of thing you can knock up in a weekend. It also takes a lot more planning in terms of the pipework needs. Because once it goes in, changing your mind afterwards is an awful lot of work.

If you were in perth I would offer to do the job for you

Are you a fibreglasser mate? What would your advice be as to the best way for me to find the air exclusions under the gelcoat in my grow-beds. Shining light on? Poking and prodding and waiting for it to break?

I've had some experience

You could use a firm piece of plastic (plastic will not scratch too badly) to tap in and around corners or the best way would be to use a high pressure cleaner, if that doesn't break open the bubbles then don't make more work for yourself by trying to find more, if the pressure cleaner doesn't break them open then they probably wont break open with normal use

I played with this stuff quite a bit making model slope soaring aircraft. polyester resin is the cheaper stuff which is terrible to work with as it vents off its thinner as it sets. Smells terrible and quite toxic and dissolves polystyrene. Epoxy is more expensive but much more pleasant as it has virtually no odor as it sets and it is far more engineered in terms of the time it takes to go from liquid to plastic and then to solid. In its plastic form it can be trimmed with a pair of scissors or craft knife which is awesome. It can also be used over polystyrene and this could be quite useful for making tanks insulated. You could construct the tank from foam and then lay up glass on it. If you really want good results you need a vacuum pump to ensure that all bubbles and excess resin are removed from the layup. You lay up the glass and resin then a film with pinprick holes goes over that followed by an absorbent layer then it gets sealed in a flexible membrane and then all the air gets sucked out of it. air and excess resin bleeds out of the pinprick holes into the absorbent layer giving an very good result with no air pockets under the gel coat. Google 'vacuum bagging' to get a better idea.

Hi All
I'm new to this forum but not new to aquaponics. I made my system from fibreglass last year
and would recommend doing it to anyone that is a competent handyman.
I built a 1500 litre fish tank, 800 litre sump and three 600 litre growbeds. Working
with fibreglass is easy but very messy but easy to get a functioning product. A lot harder to
get a saleable/professional product.
Be warned though, this is the type of project that half way through you will think WHAT THE
HELL AM I DOING? however when finished will be completely worthwhile.

Costings.
Is it worth it. Fibreglass is long lasting, easily repairable and solid but is expensive compared
to IBC tanks.

example to make a 2000 litre fish tank ( 2m x 1m x1m)

total surface area of tank = 8 square metres.

I use 3 layers of 600 gsm (gram/square metres) chop strand mat.
ie 24 square metres ( 3 x 8 )

total weight = 24 x 0.6kg = 14.4 kg of dry fibreglass mat.

I usually work to a ratio of 2kg resin to 1 kg of glass hence need 28.8 kg of resin.

the cost:

fibre glass mat $3.00/ square metre 24 x3= $72.00
resin general purpose 30kg = $ 255.00
flow coat about $100.00

total = $427 plus gst plus brushes/acetone/disposable gloves etc.

hope this helps

cheers Lou

Welcome Lou, Nice first post with helpful info. Some pics of your system on your own thread would be great.
Cheers JORGY

Thanks for the advice TEA.

Nice one Trout

I've just done some specialized sized growbeds for a guy similar to this.
I'm hoping he'll post some pics of the finished Ap he's doing