Ama Hull to Deck Joint

[Fatboyfinn]

I've never been very happy about the ama hull to deck joint. Leaving aside the
asthetic implications - I was talking to the brother of a friend who worked for
Tony Smith many years ago in the UK - he was telling me horror strories of the fordeck parting
from the ama.....ummm. Anybody had that happen? To strenghten the joint and make it
a bit more attractive I was considering making a 1/2 pipe with a flange to cover the joint.
These would be made at home and temporally screwed and epoxied on after taping the original joint.
Any idears would be gratefully received.

Andy

[Andre]

Andy
Its no wonder you have never been happy with the original ama deck joint, They stink. Leak look bad and not very well executed. The side that faces the main hull on my boat has dozens of screws trying to hold the thing together. Whoo I feel better now. As to your question: the hull has an inward turning flange about 2 inches wide. The deck is glued down to this flange and has a downward facing flange that goes over the edge of the hull. On my boat the previous owner removed the over hanging flange making the side of the ama smooth all the way to the deck. This flange that wraps around the hull is not as far as I can tell a structural joint. When the previous owner removed the flange he filled any resulting gaps with faring compound. Over the years the flexing of the boat has caused this compound to crack and let in some water. If you remove the flange and glass the joint, this would eliminate the problem. But then you would have to sand and re-fare the deck to hull joint and paint. I am in the process of molding new ama decks from glass and foam. The old decks balsa core is too far gone to fix. When I cut the old decks off I will take some pictures of the hull deck joints and the inner workings of the amas and post them. (assuming the forum will accept them)


Andre

[petrel]

I agree with all of the above comments. The ama hull to deck joints suck - water that is. And look disgusting. For me fixing them is not worth my time and money. However, if I was to do it I would try to not have the black rubber bumper that surrounds the boat. I think it would look better without it and it would definitely save a lot of weight.

I look forward to seeing Andre's and Sandeb's ama modifications. They should significantly reduce weight and windage and improve performance.

Good luck
Geoffrey

[ajaxpc]

A previous owner glassed the joints on Trina.

These still look OK, and certainly don't leak.

You can see what they look like here:

http://telstartrina.blogspot.co.uk/2011/04/trina-ama-stern-deck-repair.html

I've noticed some fine cracks appearing just above the joint in one or two places. They aren't the only gel coat cracks I have, though. (!)

[Andre]

I have removed the deck from my 26 mk1. The lap joint facing the main hull was completely de-bonded with only screws holding it together. The deck core was rotted with not one intact area. I have molded a new deck with foam core and am getting ready to bond it to the hull. I have posted some pictures on Photobucket and if I am doing things correctly they will appear here.

Andre

[ajaxpc]

Wow!

It makes what I'm doing to Trina look like tinkering!

I'm just going to cut out the areas of deck with rotten balsa and glue new ply decks on top of the what remains of the old ones. Not elegant, but it keeps future options open and solves the problem within my present means ... and maybe gets me sailing sooner!

Alex.

[Andre]

Alex
I think your method is the only viable alternative to replacing the whole deck. The edges of the deck where it meets the hull are not cored and are very thick. If you glue and bolt/screw your plywood to these areas I think you will have a good durable deck. I decided to replace the whole deck because I wanted to try to build a large foam composite panel. It turned out to be not that difficult but it is expensive. As a result I am replacing only one deck this year and the other next year, by which time I hope to have forgotten about the fiberglass itchiees.

Andre

[JoeWalling]

I find all this really interesting. I think I posted elsewhere that I plan to widen my boat and maybe make her fold.

The boatyard where my stern extension was done asked me last September to run their admin department and I have been there ever since, as has HUSH. You might imagine this puts me in a privileged position when it comes to HUSH projects! I plan to relaunch shortly and do some research in the summer with a view to carrying out the work in the winter. So any ideas will be greatly received.

I may also install a wheel. The wheel would be sited approximately just aft of where the aft locker doors are currently located. There would be a floor to stand on behind that, in the space occupied by the old transom and there would be a seat moulded in, on or about the join to the extension. From the side it would look as it is now because I really like those lines.

Cheers. Joe.

[ajaxpc]

Andre -

My decks had rotten patches, but also quite a lot of dry balsa. A problem I had was not knowing how far the bad bits extended.

I might have been able to save more of the original deck by taking out sections at a time, but (a) I didn't have time and (b) I felt I could still end up replacing the whole lot.

A man in a boatyard explained a method to me that involved cutting the top later of grp, scraping out all the balsa, getting the space really dry, and then epoxying in a new balsa core and covering it with epoxy and glass. I decided this would only be feasible if I was working under cover.

Anyhow - my new decks are now on, though there is still some finishing to do:

http://www.telstartrina.blogspot.com

Alex.