bolt right through deck of Avon 340

farmnic · 24 September 2011, 18:47

Hi folks
I am new to RIBs (but not to boating). I have bought an Avon 340 of uncertain age but in reasonable condition. There is however a feature which I suspect may not be original:- near the front starboard area of the deck (behind where the deck starts rising to the bow) there is a 12mm stainless bolt inserted from under the boat's hull (with a rubber washer around the head), fixed with a nut on the surface of the deck. It looks like there has been a small repair or strengthening of the hull around the bolt head underneath. Is it normal to penetrate the hull like this? It is not needed as a drain as there is an original bung drain in the floor just in front of the transom drain.
Thanks for any advice. Nick

Poly · 26 September 2011, 11:17

Can you post some pictures? Like you say it doesn't sound original - but it may have been some sort of eye for clamping kit down / towing / lifting the boat which quite often are bolted through the hull...

farmnic · 26 September 2011, 12:54

Thanks polwart
Here are pics of the bolt, the hole underneath, and the hole at the front right of the mail deck. You can see that a previously screwed and glued console has been removed sometime.

m3mm0s rib · 26 September 2011, 13:22

Never pierce the hull to support anything from over because by this point i started to osmosis.

BumbleAbout · 26 September 2011, 16:33

It looks like the hull needs that hole filling and filler applying to the deck too (once the hole has been dried out) - that is not the place for a hole or a bolt !!

NSS · 26 September 2011, 19:53

I'd take a guess that there used to be a through-hull transducer mounted there and the bolt was a botch job repair of the hole after said transducer (and console) was removed.

jyasaki · 27 September 2011, 16:29

Why would you mount a transducer at the bow of the boat? At speed, it will be out of the water (or mostly out, anyway.)

You'd want the transducer well back, where it will be in relatively clean flow most of the time.

jky

farmnic · 06 October 2011, 14:42

ok, thanks all for your thoughts.
I have filled the holes now.
N

9D280 · 06 October 2011, 14:58

It's either a remarkably shoddily installed load spreading plate / eyebolt or a repair - If it was for liffting there would have been a symmetrical set of at least two, and the hole would (should!) have been a bit(!) rounder. Surrounding Gelcoat hints at impact / repair as well.

When I got mine it had 8 M10 holes (4 u-bolts), one in each corner (so to speak!) which thankfully seem to have been sealed & kept maintained with fresh sealant every so often, as the hull was dry in the area. The main down side was that the threaded ends of the bolts poked down about an inch & a half, when I removed the stern ones & filled the holes I got an extra couple of knots out it!

Holes through the hull are OK, IF you seal them properly and don't mind the extra drag....