Fiberglass tank testing methods/protocols/requirements

A. Hi Charlotte

You have some very good frp fabricators in Toronto ... have you tried them yet?

When one builds an frp tank, one tries to comply with the 41-GP-22 regs .... from a structural viewpoint, the tank is thought to normally sit on a flat surface (not on some beams)and should be designed for the right amount of stiffness & structural strength.

Then there's the resin. The selection depends on what the chemistry and temperature is. However, some people might well use a top resin (polyester or vinylester) for the contact areas but a cheaper (aliphatic) for the structural side.

Lastly, the most important thing is the corrosion barrier. This is normally around 1/8" thick and contains mat but no structural glass (cloth and woven roving) and has a very high resin to glass content.

However, the good and the cheap resins look alike once cured. And how does one test for a well made corrosion barrier? I don't know.

I believe that there was one test using acetone ⇦this on eBay or Amazon [affil links] Warning! highly Flammable! to ensure that the resin had completely polymerized ... but structural or corrosion resistant tests? Ha! That you leave to the integrity of the supplier.

On a strictly personal basis, I don't like frp tanks but much prefer the dual laminate, ie. PVC/FRP tanks which, incidentally, were first made successfully in the world by Alcore Fabricating up in Richmond Hill. And if you asked for Peter or Manfred, you'd get a better reply than mine.

A. Regarding the advice that was given regarding FRP tanks, there are some additions that I suggest.

First, I agree that FRP tanks should be fabricated to a recognized standard. CGSB 41-GP-22 is no longer valid, and has been replaced by CAN/CGA B149.1 . Better standards for fabrication are ASTM D3299, ASTM D4097 and ASME RTP-1.

Although a tank can be fabricated to one of these standards, it is essential that the fabricator have a verifiable Quality Control process and third-party inspection by a COMPETENT inspector is generally recommended, for ensuring that the correct materials are used and "hidden" non-conformances are detected and the equipment is made correctly.

Lastly, the acetone test is only used to determine whether resin has cured (polymerized) properly in surfaces that are potentially exposed to air during cure. There are several other QC tests that can be completed, and some new tests being developed.