Soggy Ply

[pauliebear]

Hi there, am about to pull up the teck on a 1980 transworld 41 {formosa or ct ?}as there are soft spots under the glass where water has got under the screws and into the ply between the glass . A previous owner has started the job and has drilled small holes in the glass and filled with epoxy I guess , my question is : can I just pump epoxy through the holes after it is dry or do I pump in acetone {finger nail polish remover}to force out the moisture first? any suggestions on alternative ways would be great as well.cheers Paul

[Wotname]

The best way to handle soggy ply is to remove it - completely remove any piece of the ply that is damp.

Of course this is also the hardest way to fix it but anything less is a compromise.
If you decide to compromise then you will have to work out your own risk analysis and what standard of repair you are willing to accept.

Repairing / replacing a soggy ply formed deck deck can be daunting!

[Hudson Force]

I've tried both the "drill and fill" method and the "full removal" method and I strongly favor cutting off a full panel of the deck and complete replacement. 'very important to join the repair with the rest of the deck using a wide shallow faring in the manner of a scarf joint so that you have a large surface area for the adhesion of the new material at the deck surface.

[vintageray]

Best to tear up the rotten deck and replace it. Not that bad if you do a section at a time and are careful to keep things neat as you work. I'm doing mine and have found some rotten members under the plywood to replace too. Using fir for supporting members where needed. Again, not bad if you buy or have the right tools. I'm using Dynel for covering the plywood instead of fiber glass. No itch and can installed to mimick old time canvas non skid deck. Saves a bunch since it can be painted with alkyd enamel porch paint and your good to go.

[Blue Crab]

I think that drill and fill is for small areas only. You have a big job ahead. Might want to save the beer til the end, otherwise there may not be an end to it. I'll drink to your pain in the meanwhile.

[osirissail]

Most cored decks are in fact sandwiches of a lower fiberglass "pan" into which the coring is laid and then a fiberglass skin is laid over top.
- - You can use a "slitting" saw to cut through the upper skin around the "wet" area and then carefully lift off the upper skin. Then remove the old wet coring, clean, dry the area and lay in new coring. I prefer using Kledgecell or Nidacore which are purely plastic coring materials so that any future water leakage cannot "rot" the coring. However if the area includes a mounted machine like a windlass then waterproofed marine plywood is what you use to replace the old wet coring.
- - The carefully put the removed top skin back in place and glass it back together with the rest of the deck.
- - The process is time intensive but not overly difficult or technically challenging. Just takes sweat and a willingness to get dirty. Oh yeah! wear a paper "moonsuit" and take the arm cuffs and leg cuffs. Also a respirator. FRG sawdust loves to get into your skin and give you the "itches" for the better part of a week.

[zeehag]

there are pictures of this procedure in the leaky teaky yacht club, a yahoo group. many have had to repair their decks and have placed pictures in the site. you may be interested.

[Celestialsailor]

Finally found it...Here is a thread that I replied to with my step by step of core replacement that I did. PM me if you have any questions...

http://www.cruisersforum.com/forums/...k-11074-2.html

[Hudson Force]

Originally Posted by osirissail

.......... You can use a "slitting" saw to cut through the upper skin...................Then carefully put the removed top skin back in place and glass it back together with the rest of the deck.........

I pretty much follow osirissail's plan, but I use a rotary tool like a Dremel to cut off the top layer. I've found that it works best for me to take a grinding disc and shallow out a wide surface area at the remaining seam after replacing the top layer, then layering strips of fiberglass across the widened seam. Otherwise there is potential for a crack to develop at the seam.

[zeehag]

many leaky teaky boats have a layer of fiberglass laid over the plywood of the underdeck. there is also in many a shell under the ply which creates a core situation in effect. the overlayer is replaceable more easily than saved. see leaky teaky yacht club for pictures and diagrams and the paragraph on the back.

[osirissail]

I use a slitting saw as it is faster and I can cut straight lines where I want to cut and not wander around trying to control a Dremel type tool. Also I like the minimal size cut width so I can bevel both sides of the cut when re-glassing back. Another consideration is embossed deck patterns, they can be a bitch to try to recreate.

[Celestialsailor]

Originally Posted by osirissail

I use a slitting saw as it is faster and I can cut straight lines where I want to cut and not wander around trying to control a Dremel type tool. Also I like the minimal size cut width so I can bevel both sides of the cut when re-glassing back. Another consideration is embossed deck patterns, they can be a bitch to try to recreate.

When I did mine, I used a worm drive "skill saw" with a carbide tipped blade. The old top layer was easily removed and re-epoxied back down. Saved on time, mess and cost 10 fold.

[minaret]

Originally Posted by osirissail

I use a slitting saw as it is faster and I can cut straight lines where I want to cut and not wander around trying to control a Dremel type tool. Also I like the minimal size cut width so I can bevel both sides of the cut when re-glassing back. Another consideration is embossed deck patterns, they can be a bitch to try to recreate.

What exactly is a "slitting saw"? Do you mean a circ saw with a thin kerf blade? Or a Fein multi master with a cutoff disc? Never heard that term used before.
I like a thin kerf diamond abrasive circ saw for bigger stuff and the Fein for detail work. Regular circ saw blades can cause delam and blowout.
If you can succesfully repair molded in diamond skid like new without molding a new part, I have a job for you...

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[Celestialsailor]

Originally Posted by minaret

Regular circ saw blades can cause delam and blowout.


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Huh?.........

[minaret]

Originally Posted by Celestialsailor

Huh?.........

Not saying a regular saw blade will ruin your laminate or anything. A nice sharp carbide tooth'd blade will do just fine, and the little bit of gelcoat blowout along the kerf will be ground and glassed later in any case. Just showing what I like to use. I cut G-10 and the like on a tablesaw with an abrasive blade as well. We often make our own GRP flat stock and cut it when doing custom fab. We even have a bandsaw in the shop that is setup as the permanent carbide abrasive cutter. If you want really nice cuts in glass abrasives are the way to go, IMHO.

LENOX Bandsaw Blade Construction, Benefits and Application of Bi-Metal, Carbide Tipped, Carbide Grit, Carbon Flex Back and Carbon Hard Back Band Saw Blades - ToolCenter.com

-see carbide grit blade...