Advise request on SR4 transom repair

foivos · 01 February 2023, 11:07

Dear All,

I am looking into purchasing an Avon SR4. The boat is operational, got a ride today, but I noticed upon inspection a crack in the transom hole of the flooding hull (please see attached pictures). I inspected all transom (hitting, testing for flexibility, difference in noise etc) I didn't notice anything suggesting that the whole transom is seriously damaged, but then I am certain the cracks in the images are not good health indicators. The boat stays continuously in the water during the summer months (which is not good, but is what it is ...). Now, I really want to acquire an SR4 (they are VERY hard to find here in Australia) and I am after some advise, based on the usage I do (the boat stays inside my garage and goes out once per month if I am lucky - it will be used as a dive boat). Do you think I am getting in awful lot of trouble? I don't know much about glassing but I am a quick learner. Any advise most appreciated on how to repair this. I basically hope that I can patch it, and given my usage, it will last for the next 5 years or so. If it requires complete transom rebuild (take floor out etc) I cannot go for it now.

Thank you for your time

paintman · 01 February 2023, 13:35

Will have had water soaking into the ply & just tapping it isn't going to give you much of an idea as to what state it's in.
Might have a look at this thread. http://www.rib.net/forum/f8/major-se...ild-17490.html Post #18

foivos · 01 February 2023, 14:16

Thank you for your reply. It was pointed to me out that some SR4 don't have plywood below the deck, as suggested here, it might be pure fibreglass (below floor)?

Steve509926 · 01 February 2023, 19:41

From those pictures it looks very much like the ply has delaminated. As paintman has already said, if it's been sat in the water all summer it will probably have soaked up a lot.

There aren't many non invasive / non destructive test you can do to assess how bad it is, but two simple tests you can try are:-

1. Place a straight edge across the hole. With the middle of the straight edge pushed against the hole, see if there is a gap at either end between the transom and the straight edge. If there is that could indicate that the transom has taken on water and is swollen.
2. Using a long thin metal skewer, see how far you can push the skewer into the crack before feeling any meaningful resistance.
If you can push it into the crack a fair way, that would indicate delamination. If it comes out with dark, wet bits of wood stuck to it that would indicate rot.

Even if both tests appear to be ok, it doesn't prove that everything is good.

Good luck.

Peter_C · 01 February 2023, 20:19

It is possible it was dropped onto the transom as the gel coat is broken there. The question is how long has the wood been exposed? As Steve suggested use a thin sharp pointed object to probe around.

If the rest of the boat appears decent, might be prudent to call in a professional surveyor to asses the hull.

Might even be able to inject Epoxy into the cracks and get another 10 years out of the boat.

foivos · 02 February 2023, 08:16

Thank you very much for all the help and advise.

beamishken · 02 February 2023, 17:03

Quote:

Originally Posted by foivos

Thank you for your reply. It was pointed to me out that some SR4 don't have plywood below the deck, as suggested here, it might be pure fibreglass (below floor)?

I've replaced the transom in a couple of sr4s & they didnt have wood below the floor at the transom. What you may be seeing is a lump of bonding paste that has squeezed down as the floor was bonded down, if I were you I have a gentle probe with a thin flat screwdriver & see how it goes if its wood it will be soft & easy to penetrate but I suspect it will be hard & the crack is cosmetic & just needs a little epoxy or gelcoat to tidy it up

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Steve509926 · 02 February 2023, 17:41

Quote:

Originally Posted by beamishken

I've replaced the transom in a couple of sr4s & they didnt have wood below the floor at the transom. What you may be seeing is a lump of bonding paste that has squeezed down as the floor was bonded down, if I were you I have a gentle probe with a thin flat screwdriver & see how it goes if its wood it will be soft & easy to penetrate but I suspect it will be hard & the crack is cosmetic & just needs a little epoxy or gelcoat to tidy it up

Sent from my SM-G950F using RIB Net mobile app

Practical 1st hand experience is always the best

beamishken · 02 February 2023, 21:10

Quote:

Originally Posted by Steve509926

Practical 1st hand experience is always the best

Just had a look at another I have laid outside & its the same, no wood below floor level. Due to the long production run things may have changed over the years, but theres every chance the ops boat may be the same as the ones I've looked at.

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foivos · 03 February 2023, 01:03

Thank you very much, this is super helpful for making an informed decision for the boat. Thank you!!!!

Philelmes · 25 May 2023, 21:47

as this is a transom related question i thought it best to hitch hike this thread.

my 1970's sr4 needs a new transom....who'd have thought and shock horror haha.

my question is, as the tubes need to be removed to get to the edges, does anyone sell the replacement Hypalon bands (pre cut to size and shape) to refit the tubes to the transom? as its a well known make and obviously many need repairs, i kinda thought they'd be available rather than cutting them yourself.