Foam core replacement
 

I was walking on the deck of my project boat I just bought for the first time and I noticed the floor was soft in many spots and the foam core has rotted out. Its really bad, About 70% of the deck! I have read that it is possible to cut off the top layer of glass as a big sheet, Replace the foam core, Then glass the top sheet back on. Can this type of repair be done on such a large scale? And what would the best way to go about this problem? I had plans to repaint the boat so the paint factor doesn't bother me as long as I can get the deck to look nice and flat after the repair is done. I really fell in love with the boat and don't want to cut it up. But at the same time I don't like putting band aids on things and would like to go about this the right way.... If there is one.

Any and all advice will be greatly appreciated!

any pictures?

I tryed to take some pics but the boat is dirty and I couldnt get a reflection. I took one of the hatches out where I think the whole problem started to find that the core is still there (in bad condition) and it looks like the water had delaminated it from the glass on both sides.

Can this be done
 

from the underside, any way to pull the deck?

Billy

I'm looking into that possibility right now. It seems like it would be worth the time to do If I can save the finish work involved with cutting from the outside layer. I have done some research and found the basic steps required to do the repair and I feel pretty confident I can do the job well. I noticed people are using many different materials/epoxies etc when doing the repair. What are the best materials to use for this type of repair? I havent found any information on what would be best to use for joining the new foam to the existing glass and was looking at this Grid scored scrim Divinycell foam core.http://www.jamestowndistributors.com...+-+Grid+ScoredIs this scored stuff the way to go for a curved surface like a deck? Its got more of a price tag than the un scored sheets. I was thinking maybe I could use the cheaper un scored stuff in the middle where there isn't as much of a contour then run the scored core down both outer sides where the contour is greater. Would this be ok to do?

Vaccum bagging will help in some flat spots but that is hard for a side or angle or contours. Scrimmed and scored is best it contours and your going to be glad you did it. For the deck glassing will be pain upside down, remove the dead material, grind, putty the core up putty over it and then install 1 layer of mat and some 1808 over that in sections, dead cats, . Lay them up on the floor on some card boad or lay it up on some plastic and then hold it up and peel the plastic off and roll as usual. The mess will be less and it gives you a chance to roll all of the extra resin on the work surface for the next piece and so on. Dead cat like piciking up a dead cat off the road. LOL Any questions buzz me Monday.

Billy Kosick

I plan on painting the deck red and though it wont be as bad as black I would suspect the deck to reach some higher temps from the sun. What epoxy resin do you recommend I use to join the core to glass? Also, You said to lay new glass over the repaired core. Could I just save and use the layer of glass which was removed to replace the core, Then just lay new glass over the seams? Im not looking to cut corners but any chance to save $$ would be great!

No, you should plan on glassing with fresh materials. To bond the glass back on would be a mistake. Bond the core grind outside that and glass. Just like new.

Billy

make sure that any wet coring is removed and that you have everything dry before you start to repair the deck. Also if you are gutting it be ready to support the shell while you work so that you dont have anything crack, break or belly.. ;) Jamie / Lakeside

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How much support does the deck need when being lifted? Is it strong enough to lift from a single spot in the stern and bow so I can just spin it like a rotisserie? If not whats the best way to flip it? Could you maybe post a picture so I can reference the lifting setup you guys use for ideas? I'm also trying to get the boat as light as I can during this rebuild and Its killing me to put wood back in. I was actually thinking about replacing all the wood I stripped from it with foam core if I can afford to do so. Do you think there would be much weight savings by doing this?

You want to make a jig on top of the boat before you do any work. Then when lift off the deck and flip it over you will not have any distortion.

Jon

You may be able to get away with some smaller decks in lifting them in 2 spots. However I wouldnt if you dont have to. You would be best spreading out the load, even if it is with 2x4s.. like building a lifting frame for the deck.

If you have the time & space to build a jig for the deck to roll ot once it is off that is a good idea that audifin had. However it is not always fiesable.. But if you can do it the deck repair & new layup will go faster & easier than working upside down.

I have one we are redoing now, it is a real PITA.. All of the coring was wet & rotted.. :angry-smiley-055: ..

Jamie / Lakeside


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I figured he could aways pull it outside to do the flip.....

It is bad enough doing stringers but being upside down.... there is not enough money in the world to get me to do that....
You glass guys are a few short of a sandwich anyhow so

Today I looked into building a lifting jig like you guys suggested. I'm not sure how many mounting points I should have. Could I get away with a total of three mounting points instead of 4 like in the picture below? It would save a decent amount of work. What would be the best way/areas to tie into the deck? I was thinking maybe I could screw into area's such as where the cleats were. Will this be strong enough? I also noticed the bow does not have anything solid to tie into besides a single cleat about 3 feet back from the very tip. Would I be crazy to drill a hole through the deck for mounting purposes and fill the hole after I place the deck back on?

Here is something along the lines of what im thinking:
Blue would be mouting points and Yellow would be for lifting/rotating.

http://i31.photobucket.com/albums/c3...oatsupport.jpg

REALLY appreciate all the help guys!!!

That looks good except for I would use plywood instead of the cross bracing that you have. Call me capt. overkill but I know from working on houses that stuff can move on you. You just want to make it as stiff as possible. IMO using cleat holes is fine. I would use a backing plate under the deck while you lift the deck. This could be a piece of plywood, 2x4 anything. You can also used the same idea to sapport the bow. Run a 2X4 up the middle of the boat while you lift it. Once you have it flipped over then remove the 2X. Remeber the stiffer this thing is the better the job. Don't rush it. Once you lift off the deck make sure that you sapport the hull sides as well. Depending on how long it takes you to do the rebuild the hull can distort as well.

Jon

Hmm Plywood is a great idea..Would be stiffer and faster than the 2X4's. I went to the shop to take some measurements and come up with a material list. Here is a quick sketch of the final framework I came up with. Before I buy everything I would like to know what you think.

The blue is supports that I can mount directly to kleet areas and the green is supports that I'm unfortunately going to have to drill through the deck and patch the holes when I'm finished. I'm going to use your idea to wrap the whole thing in plywood in order to lock it all together. I'm also going to pick up some swiveling wheels I can mount on top so when I flip it I can roll it around the shop.

http://i31.photobucket.com/albums/c3...tsuport2-1.jpg

I hope to get this all done tomorrow if the weather permits!

All your mounting points are only in contact with a few places. The problem that I see with that is once you pull the core the parts in the middle will want to deflect. IMO what you want to do is to have as many contact points to the deck as humanly possible. You also need to make sure that your deck will not flex or twist front to back and side to side. You probably only need a few places to actually lift it off. You will need a LOT of contact points to keep the thing in shape when inverted and the core reomoved. You can used cardboard templates to help you contore your wood to the hull.....

Jon

Yes, I plan to do alot more bracing on the inside of the framework to "cup" the deck and keep everything in place when its upside down but figured it would be a little much to sketch out. The main thing I was concerned about was the weight of the entire deck and how much support it would need when being lifted. Should these 7 main points be enough to safely lift the deck? How does the factory go about lifting a finished deck into place when they cant drill holes?

I would not drill any new holes. Once you loosen it you can slide straps under the deck to sapport it. The deck is lighter then you would think it would be.