Rotten transom

Watchemrocks! · 04 December 2006, 01:10

Hi Guys, I'm brand new to this game, but I'm learning a lot. I just bought a 98 SR4, good tubes, no patches. Elephant trunk was missing so I ordered a replacement from England because those parts weren't due to be shipped to NC Service Station for 2 months. When I began to install the transom sock, I was unpleasantly surprised to find that the transom core was soggy and significantly rotten. I have owned numerous whitewater hypalon rafts from Avon and so assume that they are high quality from stem to stern. What gives? Surely in 1998 they installed a good grade marine ply in this little boat, but it rotted impressively. My buddy told me I worry too much and said hang the engine on it and says he guarantees no problems. Couldn't do it! By the way the professional people I talked to don't seem to do transoms over here. I used a heat gun to separate the hypalon flaps allowing me to remove the metal strip and access the top of the transom. Chiseled out about a quart of "soggy punk wood". On the side where the transom sock was missing the damage was much worse. The wood intended to bolt from the floor brace was sponge. The good news is that the rot seems to extend downward and medially and I have sufficient decent wood to dry and bond to. I plan to use CPES from a company in Seattle, Washington to restore the mess. Is it true that freshwater not salt is the main cause? My opinion of marine grade plywood is not high unless it is Okume mahogany.

jwalker · 04 December 2006, 10:39

Marine ply can still rot, it is wood after all. It's the adhesive that's water resistant. It is true that fresh water causes rotting more than sea water. Fishermen in this area often leave some salt water in the bilges to protect them.

I would never rely long term on a bailer which is just screwed and sealed in place. There are a couple of threads on the forum describing how to do it properly. Here's one.

Watchemrocks! · 04 December 2006, 14:15

Good info, Thanks! I suspect rainwater and temperature extremes from outdoor storage caused my problems. A good boat deserves good care.
AJ

pathalla · 05 December 2006, 02:50

[.

With all due respect to all, I think that the majority of people here (except from VERY FEW) are not experts on building RIBs or anything much really and whatever advise you get needs 3ple verification (trust been there, done that and unfortunately got the T-shirt ) but have learned my lesson.

sounds like excellent advice to me...

pathalla · 05 December 2006, 03:27

. I was unpleasantly surprised to find that the transom core was soggy and significantly rotten. I have owned numerous whitewater hypalon rafts from Avon and so assume that they are high quality from stem to stern. What gives? Surely in 1998 they installed a good grade marine ply in this little boat, but it rotted impressively.

all boats can rot if they have wood...

pathalla · 05 December 2006, 03:44

Quote:

Originally Posted by Watchemrocks!

Hi Guys, I'm brand new to this game, but I'm learning a lot. I just bought a 98 SR4, good tubes, no patches. Elephant trunk was missing so I ordered a replacement from England because those parts weren't due to be shipped to NC Service Station for 2 months. When I began to install the transom sock, I was unpleasantly surprised to find that the transom core was soggy and significantly rotten. I have owned numerous whitewater hypalon rafts from Avon and so assume that they are high quality from stem to stern. What gives? Surely in 1998 they installed a good grade marine ply in this little boat, but it rotted impressively. My buddy told me I worry too much and said hang the engine on it and says he guarantees no problems. Couldn't do it! By the way the professional people I talked to don't seem to do transoms over here. I used a heat gun to separate the hypalon flaps allowing me to remove the metal strip and access the top of the transom. Chiseled out about a quart of "soggy punk wood". On the side where the transom sock was missing the damage was much worse. The wood intended to bolt from the floor brace was sponge. The good news is that the rot seems to extend downward and medially and I have sufficient decent wood to dry and bond to. I plan to use CPES from a company in Seattle, Washington to restore the mess. Is it true that freshwater not salt is the main cause? My opinion of marine grade plywood is not high unless it is Okume mahogany.

Have seen and worked on many "wet' fiberglass boats, transom and stringer replacement a not uncommon repair on cruisers in the Great Lakes. Many good boat builders fail at properly sealing off the wood components of a hull, the inevitable result is rot and failure. A good source for information on repair and products for repair is Gougeon Bros http://www.westsystem.com/ excellent products from an excellent company. Make sure when you attempt your transom repair ALL wet or rotted wood is removed, good luck!

jyasaki · 05 December 2006, 17:13

Quote:

Originally Posted by Watchemrocks!

When I began to install the transom sock, I was unpleasantly surprised to find that the transom core was soggy and significantly rotten. I have owned numerous whitewater hypalon rafts from Avon and so assume that they are high quality from stem to stern.

A couple of dive buddies I know bought a 20'-ish Avon RIB (not too old; maybe '02?) off E-Bay a while back. After noticing their motor bouncing a bit (in relation to the rest of the boat), they took it to a local boat repair guy. The transom was found to have lost about 40% of the wood that was originally there.

Ended up having the entire transom removed and rebuilt (wood-less, this time), at a cost of about $3k. I believe that Avon picked up the tab.

In any case, a call to the manufacturer (or their local reps) will only cost you a couple of bucks, and may end up saving you a bit of money.

jky

codprawn · 05 December 2006, 20:22

I suppose it's difficult for the makers - no matter how well they seal a transom idiots come along and drill it full of holes!!!

Revenger keep the amount of wood they use to a minimum - thr transom being the only place where it's used.

jyasaki · 06 December 2006, 18:30

Quote:

Originally Posted by codprawn

I suppose it's difficult for the makers - no matter how well they seal a transom idiots come along and drill it full of holes!!!

Not really much of a way around that as long as owners want to install "accessories" - engine, trim tabs, FF transducers, etc.

A bit of care sealing holes up after drilling and before mounting said accessories would go a long ways in preventing this stuff.

Won't do anything for actual faults; things like stress cracking and such, but I think the rates of failures for those are substantially lower than improper procedures for mounting stuff. That's just a guess, though.

jky

Aidan · 07 December 2006, 18:05

too right codders, a friend recently relocated engine height on transom and redrilled holes. We sealed them with silicone with SS bolts and washers. when they set proud of the transom, we tightened bolts hard to compress Silicone "bung" and then gel coat over.

water will get in anywhere and spread.