Need advice on 2nd layer of CSM on boat deck

[ERock82]

I am preparing to put down my 2nd (final) layer of csm on the top of my new boat deck. I put the first layer down last weekend and it fully cured. I have sanded it down nicely and now it's ready for the final layer.

I was told that once it cures, I should put more unwaxed resin down because it won't be tacky anymore, which it isn't. Why exactly should or would I do this? My thought was to just place my dry csm down on the sanded fiberglass deck then wet it out real good with waxed resin and be done. To me, that is much easier because I won't accidentally step on wet resin and track it everywhere.

If I have to put a coat of unwaxed on, I suppose I would place down the dry csm, peel it back halfway and resin, then lift up other half while stepping on first half and resin under that. I would just thinly resin so it wouldn't soak through when I walk on it. Is there really a point to this or can I just do it the way I wanted to with just the waxed?


Another question:

Once I put the 2nd layer on, it cures and I sand it, I will be done with the main boat deck. It will then be time for the seat bases which I have pre-cut.

I am considering a couple of options for these which will sort of depend on what materials and how much I have left.

1.) Coat seat bases with epoxy only, let dry and install.

I like this because the wood pieces will stay the same. No warping, not very messy once cured and not any thicker with glass so they will fit like they do unfinished.

I would then tab all of the sides onto the deck with 17oz and foam inside base tops. Are there any issues with tabbing to epoxy? If I want to place a layer of csm on top of the cured epoxy bases, will there be any issues there?


2.) Coat undersides of all base pieces with waxed resin and let cure. I then install and fiberglass and tab as normal on top.

This is also a good option if I have the materials left over. The thing I am definitely avoiding is fiberglassing undersides of seat bases because it is just a major pain and not really necessary with the tabbing and foam anyway.

Continuing on?.

Once the bases are done and sanded, is it best to just carpet the sides and leave the top with the exposed fiberglass? The seats should protect the glass from UV rays.

Also, when I carpet, I want to just use velcro so I can remove from time to time. Any experience doing this?

Thanks in advance.

 

[ondarvr]

I'm a little confused by what you're asking, but see if this is what you're looking for.

You don't need to put unwaxed resin down first, you can use the waxed resin for the entire laminate if you want. I'm not sure why you put down one layer of CSM at a time though, both can be put down at the same time with no problems, it saves a great deal of time and materials.

You can use epoxy on the seat bases, but polyester doesn't stick well to epoxy, so that can create a problem if you plan to glass them in place, but you can use epoxy to glass them in and it will work well. Just coating the wood with polyester resin doesn't work well because it's rather brittle and will soon crack if no glass is used.

The seat bases will rot away if they aren't coated with something, foam will sort of protect them for a while, but foam eventually begins to hold water and then rots the wood.

 

[Woodonglass]

Yeah, I'm confused too. How will you be stepping on wet resin. It's like painting, You start at one end and work to the other. Roll out the resin, Lay the CSM down on top of the resin and then pour on some more to wet it out some more until it goes clear and move on. You only put it down as far as you can reach and you butt your seams up or overlap them just a bit. You will always be kneeling on Dry Deck. Did you use Un-Waxed Resin the first Time? If so, then wipe it down with acetone and start the next layer. If you use Waxed for the first layer, and it's been more than a week you might want to give it a light sanding with some 60 grit and then wipe down with acetone to remove the wax and ensure a better bond for the next layer.

Again, not sure why you didn't put this post in your original thread for your boat??

I agree with everything else that ondarvr said about the epoxy and the bases.

 

[ERock82]

I'm a little confused by what you're asking, but see if this is what you're looking for.

You don't need to put unwaxed resin down first, you can use the waxed resin for the entire laminate if you want. I'm not sure why you put down one layer of CSM at a time though, both can be put down at the same time with no problems, it saves a great deal of time and materials.

You can use epoxy on the seat bases, but polyester doesn't stick well to epoxy, so that can create a problem if you plan to glass them in place, but you can use epoxy to glass them in and it will work well. Just coating the wood with polyester resin doesn't work well because it's rather brittle and will soon crack if no glass is used.

The seat bases will rot away if they aren't coated with something, foam will sort of protect them for a while, but foam eventually begins to hold water and then rots the wood.

Thanks for the advice. I planned on putting down two but got the first layer so dirty that I couldn't. I accidentally bought 17oz biaxial cloth without the csm on the underside so I tabbed on top of the 1st layer of csm. I had the brilliant idea of using shoe covers to just walk on the drying resin of 1st layer to start tabbing, haha. Those shoe covers stuck everywhere on the resin and made a mess! I had to spend 3 hrs power sanding that stuff off. Somehow, I was under the impression that if the 1st layer with unwaxed completely cured, that I would have to pre coat the surface again with unwaxed before applying 2nd layer that would get the waxed.

If it makes sense cost wise, I think I will coat undersides of seat bases with epoxy, install and fiberglass as normal for tabbing and outsides.

Any thoughts on the carpeting?

 

[ERock82]

Update:

I completely finished the deck minus the seat bases. I used waxed for the entire 2nd layer. It took a lot of sanding with 40 grit to get it flat as there were a lot of raised spots mainly because my metal fiberglass roller wasn't working so I had to use a paint brush. I think I have about 125 hours in this so far! (That's including pre-planning, ordering materials, time spent at the store, etc.) Would be about 15 to 20 hours less if I didn't screw up that 1st deck. I'm thinking another 20 to 30 for the seat bases and carpeting.


So, I have a couple more questions on these seat bases:

1.) Since they will be screwed into the floor, is tabbing necessary? I plan on peanut buttering all of the edges that meet the floor and that meet each other. If I lay down a thick coat of this would that suffice? (The base sides are 2x3s and the tops are plywood)

2.) How many 2" foam holes should I cut out on the tops? The base dimensions are approx: 3" H X 40" L X 15" W. I was thinking just one. Should it be centered? Two holes worked well for the deck itself but that was a longer area. I just want to make sure they get filled all the way.

Also, any suggestions on the velcro idea for the carpet?

Thanks.

 

[JASinIL2006]

Not sure what your seat bases look like, but if it were me, I'd be glassing them to the deck with some cloth, not just PB. I'd think you'd want those to be as strong as possible.

 

[ERock82]

I got my seat bases installed this past weekend. They are now ready to be foamed and then will get fiberglassed. I can finally see the end of this project now. The seat bases look great but I might have screwed up. It's too late to fix but I just thought I'd mention what I did.

I attached my seat base sides to my deck using #10 3" stainless screws. The sides are 2x3s, so The screws would just barely pertrude through the bottom of the deck with the recessing I have. (2 1/2" of side + 1/2" deck) My main concern was making sure these were perfectly lined up and that my screws went through the pre-drilled holes. I'm pretty sure I accomplished that. Once, I got them screwed on, I backed out the screws and covered them in epoxy. I had problems with some coming out and thought that there was no way this epoxy would work it's way down 3" to seal up the deck hole. It seemed pointless so I only did about half. ( I really don't think it would have sufficiently sealed because of how far down it had to go). What I should have done, was to fill the holes at the deck level with epoxy, then place the 2x3 in place then screw through. Well, it's too late because I completely installed these and peanut buttered them to death. They are very sealed up.

The area in which these screws are located are over foaming which I hear is good because there won't be much or any condensation. I don't know if the foam completely filled to the top bc it didn't sound like I drilled through foam but those cavities are filled well and sound solid. I guess I am worried the deck will rot from water getting into the bottom where these screws are coming through. Unless the boat sinks, I would imagine condensation would be the only way but is it likely that with the foam being underneath that this would be a major problem? If so, I figure I will still get years out of this because it is way more sealed and solid than the original ever was.