reinforcing floor board (updtated w/ pics)

Ok, Ok. So this is long over due!

I decided to go a slightly different route with this one, and I figured I should share my results with you guys. I know it took me way to long to post this, but I was having some major computer issues.

These are the mid way pics. I decided to add inlaid aluminum trusses to add structural rigidity. aside from that, I continued to to bore out the cracks, and I filled them with a low density filler and epoxy.



I then "iced" over everything with epoxy and high density filler to cover it all up. Finally, I laid about 9 layers of fiberglass weave and epoxy without filler to build my height back up, and add rigidity to work with the aluminum trusses.

My thinking was to basically add a skeleton to this thing to prevent the same thing happening again. I kind of went out on a limb, here, but I think it paid off, as it is now rock solid! So much better.

Thanks everyone for your help, and I'll post more pics of the glassing soon.

bkhallpass wrote: If it were me, I would drizzle as much epoxy in the crack as I could to fill the gaps. build up a nice strong patch of fiberglass, and put a layer of fiberlass all the way across the panel on each side for strength. I look at it this way. The sides of the hull are fiberglass only - no core. You'd have a very difficult time kicking a hole through the side of the boat. BKH

The fiberglass on both sides of the repair is very important. The top is going to be under a compression load and the bottom tension just like a stressed skin panel. The glass is what really gives the composite the strength. The break in the existing has fractured the original glass. Just pouring epoxy into the break will "glue" it back together but it will not have the strength.

Yes, I'd take the poly resin back and look for the epoxy. Any marine supplies around like I mentioned?

jackkloepfer wrote: So I'm grooving out the cracks right now, and it appears that the material with the cracks is a foam core. I'm starting to fear that filling these cracks will not help the structural integrity all that much, as I'm basically just filling the cracks in the foam.

If it were me, I would drizzle as much epoxy in the crack as I could to fill the gaps. build up a nice strong patch of fiberglass, and put a layer of fiberlass all the way across the panel on each side for strength. I look at it this way. The sides of the hull are fiberglass only - no core. You'd have a very difficult time kicking a hole through the side of the boat.

My $.02.

BKH

So I'm grooving out the cracks right now, and it appears that the material with the cracks is a foam core.

I'm starting to fear that filling these cracks will not help the structural integrity all that much, as I'm basically just filling the cracks in the foam.

I'm grooving out the cracks with a dremel right now, going pretty well.

I was able to get pretty much all of the adhesive off of the top sheet. there appears to be tiny traces of it here and there, but it is pretty much clean.

Jack,
Do to the size of the repair needed plus the convenience in finding supplies, I'd say go to a marine supply and look for West products.

Brian,When did all this "originality" come out of you? It must be contagious!! Jack, Brian does have a very valid point regarding keeping the wood away from your boat but, if you do find the glue hard to remove, you could get a sheet of one of the composites.

Pete, remember, this boat was a 96. There shouldn't be any wood in that floor panel. I don't think using ply is a good answer.

Jack, you need to grind a v down to the crack from each side. this gives you a clean surface for the repair to bind, and also allows you to build the area back up strongly. Once ground down, you can trickle some epoxy resin in the crack itself. However, as you build up the repair you need fiberglass cloth or mat in the resin. Resin by itself is strong, but brittle. The glass gives it strength. What Chris was saying is you start with a small strip, mayble and inch. Then A wider strip and so on until you have filled up the V and created a repair 3 or 4 inches wide.   The wider the repair, the stronger it will be be. If the cracks are small, you can probably just widen them with a dremel and fill with resin, then cover with mat. If the cracks are wide, and the fiberglass has delaminated near the cracks, you need to grind away the loose material.

There should be acore of some sort of composite in that panel. Worst case, you grind down to the core, and then build the fiberglas back up to level.

I believe what Pete is saying is that once you have fixed all of the cracks, he also recommends a layer of cloth across the whole repair, probably across the entire surface of the panel, for strength. He is recommending a layer of mat or cloth across top and bottom. To do this, you need to be sure all of the adhesive is off. This means either grinding the whole surface, or if you get lucky, getting it off with adhesive remover.

Just cutting a sheet of plywood, coating with CPES, and glassing over it would be quicker. But, in my opinion, it's not the right thing to do. One of the selling points of 93 and later boats is that they have no wood in the construction. I don't think it's in your best interest to put wood in there now.

I would guess it will take you a couple of hours to grind off the surface both sides, grind out the cracks to a V. Probably two or three layers of glass to fill up the Vs, and a layer of Mat or cloth on both sides. If you did just one layer a day, you'll be done in a week.

Free advice, take it for what it's worth.

BKH

Jack,
Brian's got the repair down pretty good but he also made another good point. That is replacement may be easier! First, it may be a real PITA to get the carpet adhesive off. It's going to take time, solvent, grinding and clogging lots of abrasive disk's. To do the job properly, the crack needs to be filled but just as Brien mentioned, another layer of cloth over the top and I'd recommend the bottom too.

See how easy the adhesive comes off. If tough, consider starting over with a piece of exterior ply with CPES, resin and glass on both sides/edges.

Jack - Think of the repair as creating a very wide V groove. The depth should be to the bottom of the crack. The width need to be about 3 inches. You will want to feather the repair out level with the original surface. It will take several layers of glass, each one wider than the last.

I know that section of floor can be repaired, and I would guess it will be much cheaper than trying to replace it. I am not certain what the best method to do the repair is. Guys like pbrainard, morfoot, Dr CC and others, have a lot more experience than I do working with fiberglass.

BKH

I'm sure some of the guys with more fiberglass experience than I will be along to recommend a fix. Looking at it, I now think you may need a bit more resin, but I don't think any more than a gallon.

You'll have to grind away some glass, to get rid of the glue, and makes sure there is a clean surface for the new glass to bond. I am also guessing they will advise to grind more deeply where the cracks are, lay in some reinforcement in the cracks, and then cover with a larger swath for strength. Again, I'd listen to someone with more expertise than me before I proceeded.

That cracking is just par for the course from people hopping in and out of the boat. A 200lb person coming down on the heal of the foot can generate a tremendous amount of force. Add in moisture in a boat which can soften the lamination, and it just happens.

BKH

it looks like there might be some cracking under the 1st or 2nd layer of glass:

Epoxy is stronger than polyester based resin, and also more water proof under saturation. The auto parts stores will probably only sell polyester resin. Also, fiberglass, mat, cloth, roving is different for epoxy resin vs. polyester resin, at least that is what I'm told. You probably won't need much. Perhaps a quart or two. West Marine sells it, but they are pricey. You can probably also get it at Tap plastics. Most guys here doing major repairs/stringer jobs buy their materials from US composites. There is a lot of information about fiberglass repairs/materials in any of the stringer/floor threads.

In terms of glue, I have not seen a recommended brand. I know several have used outdoor carpet glue which they picked up at Lowe's, Depot, or Ace.

I'm not the fiberglass expert. I've only done patch work on surfboards, boats, etc. I'm perhaps a third of the way through my first stringer job, and have not yet purchased my resin or glass.

BKH

If it comes off without ripping, there should be no reason you can't glue it back on.

BKH

Ok, that makes perfect sense. Thanks.