Aluminum vs Fiberglass RIB

[djousset]

Despite my optimistic resuscitation efforts the old Mercury has finally given up the ghost.

In a new RIB, relative to the hull, I am looking at both aluminum and fiberglass. I understand there is a weight difference, and perhaps strength variances. Are there any other meaningful considerations in choosing one over the other?

[MicHughV]

Depends on how you plan to use it. If beaching it everyday, my vote is for alum.
If simply tying up to a dock, I'd go fiberglass.

[hlev00]

I love many things about my lightweight aluminum RIB. The two issues I have are 1) it is powder coated and that is starting to fail after 3 years and manufacturer won’t stand behind it. Better to avoid powder coating. And 2) it is so light that I am afraid it will flip when towing without the engine on it, and I never want to do any significant towing with the engine on. It flipped once when we were on anchor and a storm came through. It has weathered storms with the engine on. I sometimes think maybe towing with it half full of water might be worth a try.

[SailFastTri]

If you want to plane, Highfield has the best hull shape and will give the smoothest and driest ride in waves.
If you want to use a small-light motor, Highfield or AB will both provide a very dry ride (less splashing up over the tubes) with Highfield being drier.
People will say larger tube diameter will be drier, but that’s only part of the picture. A deeper V hull shape will displace more water than a shallower V, and the tubes will sit higher with the deeper V.
Fiberglass is easier to repair, and is not subject to electrolysis. It’s a better choice if you plan to paint it with antifouling and keep it in the water full time. If the coating on aluminum is scratched you will get electrolysis if the boat is allowed to sit in the water. If you want to paint aluminum with antifouling you will need an intact barrier coat of epoxy and the bottom paint must be specially made for aluminum (no copper).

[SailFastTri]

Originally Posted by hlev00

I love many things about my lightweight aluminum RIB. The two issues I have are 1) it is powder coated and that is starting to fail after 3 years and manufacturer won’t stand behind it. Better to avoid powder coating. And 2) it is so light that I am afraid it will flip when towing without the engine on it, and I never want to do any significant towing with the engine on. It flipped once when we were on anchor and a storm came through. It has weathered storms with the engine on. I sometimes think maybe towing with it half full of water might be worth a try.

You’ve now had enough experience to know towing or leaving on a mooring in open water is a recipe for problems. Leaving the engine attached while towing in open water is a mistake. Did you also leave the fuel tank in it, unsecured?
Partially swamping it is not the answer. Stop this and learn from your mistakes.
You either need a way to bring it aboard and stow it safely, or you need a lighter or larger tender (maybe one of each) appropriate for your intended use.