I have two lids that make up the back deck area on my boat. They seem to be cracking when I step on them. They hold me just fine, but they make a cracking sound every time I step on them. I weigh about 170, and it holds fine.

My question is, how could I make new lids for this back deck? Would I make it out of plywood or would I make it out of fiberglass? or a combination of both?

Could I take the lid that is on there, make a mold of it and use the new mold for the lids?

Not sure what would be better. I know adding that much plywood to the back may make it alot heavier back there, but I know it will be sturdy enough to hold someone larger than me. Just don't want my fishing partner to go through these in the future. I will try and post some pics later. I took some pictures of it and need to post them.

Any ideas?
Thanks,
Eric

Kingfisher, there is a material available called "starboard" that can be worked just like wood..........see the link below. Its the same stuff that cup holders and binocular holders are made from.
http://www.jamestowndistributors.com/userportal/search.do?categoryName=StarBoard%20Plastic%20Supplies&categoryId=599&refine=1&page=GRID&history=saz07tl2%7Ctop_category%7Cpage%7EGRID%5EcategoryName%7EWood%252C%2BFoam%252C%2BStarboard%5EcategoryId%7E305

Wow , that stuff is expensive. Probably really good material, but very expensive for me. Thanks for the link though.

west marine carries starboard, they're real proud of it, too. I made my back deck out of 3/8" BC EXT plywood with one layer of fiberglass cloth. Coated the edges and both sides with fiberglass, just used cloth on the top. Adds strength and makes a pretty good non-skid surface. Doesn't look too bad either. If you're spanning more than 10 or 11" between supports use 1/2". Couple layers of fiberglass on both sides really adds strength. I added a piece of 1/4" ply to reinforce the area where the pedestal base is installed. With temps around 75� you have to use about 2 1/2 times the hardener and it still takes all night to cure - below 70� I wouldn't even try it unless you have a warm garage or heat lamps.

What did that run you jtexas?
What exactly is BC ext plywood? Is that marine plywood? Where did you get that at? My pedastal seats are in between the two lids, so I don't have to worry to much about that. It is in good shape.

I gathered this information from various sources over the years and I'm pretty confident it's mostly correct, but if anybody notices any mistakes please jump in and correct me:

plywood is graded according to the appearance of the outside layers - "A" would have no blemishes or knots, you could use it for panelling or furniture or something. BC means one side looks pretty good and other looks worse. It's what home depot usually has on the shelf. EXT is exterior grade, which is made with waterproof glue. Protected with fiberglass I expect it to last a dozen or more years - it'd probably do even better with paint or marine carpet. Left outside, non-ext will delaminate in a few days.

Marine-grade ply is the same as EXT except it's guaranteed not to have any interior voids which makes it stronger and more durable. It's incredibly expensive - it's what you'd want if you were building a hull. The guy at west marine told me of a local dealer but I forgot where they are - you can find online vendors.

If I recall correctly, a gallon of poly resin at BPS is around $25, the glass cloth maybe $10 or $14. Plywood at home depot, they have 4x4 and 2x4 panels if you don't need 4x8.

If you never worked with fiberglass, you're in for a fun time. Get a box of vinyl or latex gloves. A measuring cup you can throw way when you're done. And a plastic bowl to mix it in. Don't mix more than you can use in 10 or 15 minutes (longer in cold weather). For me that's about eight ounces max, I mostly work with 4 ounces at a time. Above about 85� your resin mixture will start to gel in 5 or 6 minutes.

I suspended the panels from the ceiling and brushed on a thick layer of resin without hardener. Gave it a couple hours to absorb that, then brushed on resin mixed with hardener (bag of cheap "chip" brushes from HD - you can only use 'em once). Cut the cloth a little bigger than the panel and stick it on while the resin is wet. It'll stick to your fingers so use the brush to spread it out. Brush on just enough additional resin to saturate the cloth, it becomes transparent when wet. Use a plastic spreader to squeeze out excess resin and air bubbles - if it cures with any air in there it will delaminate.

Try to wipe away drips from the edges as it hardens - they ruin the fit and are heck to get rid of after they cure - I ended up using a grinder bit in my electric drill.

After it cures trim the excess cloth away with a utility knife. If you're adding another layer of cloth, do it while the 1st layer is still tacky to get good adhesion. If you leave one side without cloth, that side might be tacky for days.

have fun!

Seems like it won't be as fun as you mentioned. Thanks for the tip though, sounds as if you done alot of this work before.

I used 3/8 aluminum with 1 inch angle for reinforcement about $150 in materials.

12 years ago now but, have never worried about it again.

almost the way my back lids are made.

That lid looks nice and well done.

Here are some photos of mine:

that looks outstanding, blue. nice fish, too.

this boat (1980 kingfisher trihull) didn't have a deck in the back before I built this one - backseater had to deal with battery & fuel tanks underfoot, what a mess. These pics are the first version - interior ply, painted - it lasted about 18 months. too slippery anyway. deck lid has since been replaced. think I'll move the side compartment hinges to the middle like kingfisher's







If you're going to use rubber-backed marine grade carpet, I bet painted exterior plywood would hold up. rustoleum makes an oil-based topcoat that goes on over a water-based primer. I bet 3/8" ply wouldn't add noticeable weight over the fiberglass.

That looks good jtexas. I think you are right about the plywood over the fiberglass. I don't think it would be that much differenc in weight at all. Those lids are heavy anyway.

On the piano type hinges, what kind would you get so that it doesn't rust out? Do they make those stainless steel? Seems like the ones I looked at were like $10 bucks for a hinge. Is that about right?

home depot has zinc plated and brass plated - I went with butt hinges cause I couldn't find stainless steel piano hinges at BPS or academy. Maybe try West Marine? probably costs a bit more.

I bet they are a fortune at West Marine. That place is crazy high on their stuff. Although they usually have what your looking for in there.