Floor and Transom Rebuild

[b646]

I am removing the entire floor and transom on my 21ft Southern Skimmer. It had a leak so the floor had soft spots then I discovered that the foam underneath was waterlogged. I am new at this but pretty handy. I have watched a lot of videos and read until I am tired of reading. I am replacing the floor with marine grade plywood and will be gel coating. I keep reading different opinions on witch resin and fiberglass to use. Can I get some advice?

 

[sphelps]

Welcome aboard ! Well seeing as you want to gell coat .. Polyester resin with 1708 cloth and csm mat is pretty standard material ..
Better core sample the stringers also ...

 

[Scott Danforth]

welcome aboard

suggest reading a bit more, specifically links 14, 15, 18, 2, 3, 4a, and 4b here. https://forums.iboats.com/threads/how-tos-and-other-great-information.283508/ look at every picture, watch every video. after that, you will have the knowledge to tackle your project.

we are here to help if you have questions. we like pics.

 

[b646]

Welcome aboard ! Well seeing as you want to gell coat .. Polyester resin with 1708 cloth and csm mat is pretty standard material ..
Better core sample the stringers also ...

That's what I was thinking but wanted to make sure. I will be checking the stringers as well. Thank you.

 

[b646]

welcome aboard

suggest reading a bit more, specifically links 14, 15, 18, 2, 3, 4a, and 4b here. https://forums.iboats.com/threads/how-tos-and-other-great-information.283508/ look at every picture, watch every video. after that, you will have the knowledge to tackle your project.

we are here to help if you have questions. we like pics.

Thank you, I will check the videos out. I'll get some pictures on here soon I hope.

 

[Emerger]

I am removing the entire floor and transom on my 21ft Southern Skimmer. It had a leak so the floor had soft spots then I discovered that the foam underneath was waterlogged. I am new at this but pretty handy. I have watched a lot of videos and read until I am tired of reading. I am replacing the floor with marine grade plywood and will be gel coating. I keep reading different opinions on witch resin and fiberglass to use. Can I get some advice?

The "down and dirty" is to simply use polyester resin. It's inexpensive and will suit your purposes. You can if you want to use epoxy like West Systems. Epoxy takes longer to cure than polyester so you have to time it different. Epoxy takes a good 24 hours to cure so there's some downtime in using it. Polyester can cure in less than an hour so it's quicker. Two layers of 1708 biaxial mat over plywood will be plenty enough for a floor, but you can use more if you want to.

I've seen Southern Skimmers before but I'm not sure how they're built. They may have conventional stringers or the floor might be laid on top of the foam like a Carolina Skiff. Replacing the floor is pretty much the same either way. Just be sure to coat both sides of the plywood and especially all the edges to avoid from absorbing water.

 

[b646]

Here are some pics. Pics 2 and 3 are just general pics of the boat to give you an idea of the layout. First picture is where we removed the floor with the soft spot and discovered the saturated foam. Last pic is where water is draining out of the transom after I removed some hardware. Most of the floor and foam has been removed now. Trying to find wood and a source for materials. Thanks for all the help so far.

 

[GSPLures]

Most people on the forums use US Composites unless you have a local place that you can get fiberglass supplies from. I was going local until they increased the prices. I just got my first order from them and they were great. I called in my order and it was shipped from Florida to Michigan in 4 days.

 

[Emerger]

Here are some pics. Pics 2 and 3 are just general pics of the boat to give you an idea of the layout. First picture is where we removed the floor with the soft spot and discovered the saturated foam. Last pic is where water is draining out of the transom after I removed some hardware. Most of the floor and foam has been removed now. Trying to find wood and a source for materials. Thanks for all the help so far.

Any wood you need for it can simply be bought at Home Depot. For a floor, you really don't need marine grade plywood. You can choose to use marine grade plywood if you want to but there's no real advantage to it.

I can tell from your transom picture that it is definitely rotten based on the dark ugly water coming from it. You need to check your stringers as well. As some have already posted above you can drill holes into them to check the condition of the wood if they have wood in them which they likely do. If you have to remove them measure the originals before you do. It will make it easier to cut out new ones.

 

[Scott Danforth]

where are you located, we can point you in the direction of local fiberglass shops.

agree with everyone above, your transom and stringers are shot so your looking at a full restoration. make sure you make a cradle for the boat

standard ACX plywood is all you need.

 

[b646]

Well, I have at least 2 rotten stringers. What material should I use to rebuild them? It appears that are currently plywood. Also the first pic is off the transom. Do I need to sand it all off or just make sure I get all the old wood off and attach the new transom? Second picture is of a section where I removed all the foam. That’sa lot of work.

 

[88 Capri (2022 SOTY)]

I used 3/4" exterior grade plywood for everything.....stringers, transom and floor. All wood must be encapsulated (coated with resin and csm) or at bare minimum with a couple coats of resin. You need to remove all wood residue as well as gelcoat to get down to clean fiberglass otherwise you would not have a good bond/adhesion between new and original fiberglass.

 

[b646]

I used 3/4" exterior grade plywood for everything.....stringers, transom and floor. All wood must be encapsulated (coated with resin and csm) or at bare minimum with a couple coats of resin. You need to remove all wood residue as well as gelcoat to get down to clean fiberglass otherwise you would not have a good bond/adhesion between new and original fiberglass.

Ok, thanks

 

[b646]

where are you located, we can point you in the direction of local fiberglass shops.

agree with everyone above, your transom and stringers are shot so your looking at a full restoration. make sure you make a cradle for the boat

standard ACX plywood is all you need.

I’ll located at Holden Beach NC

 

[GSPLures]

I found it a lot easier to remove foam with an angle grinder and a cupped wire wheel attachment. A respirator and safety goggles(not glasses) is a must, also at minimum a long-sleeved hooded shirt and pants. It will turn the foam to dust and go everywhere.

 

[KJM]

I got most of my foam out with an ice chopper. As for the transom, I personally would sand that old thickened resin just enough to get any lingering wood off and rough up the surface , fill those couple of places where the old stuff chipped off with new thickened resin and then stick the new transom onto the roughened surface. Don't think there would be any advantage in removing all that old resin completely. Others may have different opinions though.

 

[b646]

Getting ready to build the transom out of 3/4 plywood. Will 5200 hold the two pieces together to make it 1 1/2 inches or do I need to use resin and cloth? I’ve seen and read about both ways.

 

[todhunter]

I'm sure 5200 would probably work, but it may be more expensive than some resin and cloth, and will likely take longer to cure...if either of those are a concern.

 

[GSPLures]

Resin and cloth works, I used PL premium to bond the 2 pieces together then when it was dried I used PB to bond the wood to the hull

 

[JASinIL2006]

I would not use 5200 to bond the two pieces of plywood together. That stuff can take a really long time to cure and there are better adhesives for the job. PL premium would work, but after using it you'll need to wait at least 72 hours as it cures and offgasses. A better choice would be either resin and fiberglass, or Titebond III. Titebond is probably the easiest (and least expensive) to use, and it cures/dries overnight. When dried, it is at least as resistant to water as the glue that holds together the plies in exterior plywood, meaning the plywood glue will fail before the Titebond if it gets wet.

I agree with the suggestion to use peanut butter/thickened resin to bond the transom to the hull. As soon as it cures, you can continue glassing. If you use PL Premium, which also would work, you again have to wait another 72 hours (and probably longer if it's cool where you're working.). If you try glassing too soon over stuff that was adhered with PL premium, you're liable to get bubbles in your fiberglass.