Bonding Stringers to Hull

[JamesGSY]

Hi Guys. I brought an old 4m RIB last year, the boat cost £750 including the engine (40hp Mariner) and trailer. I knew the boat would need a bit of work eventually but I managed to get some good use out of it last summer. Unfortunately the time has come to replace the deck as it had become far too spongy. I removed the old deck and found almost all the stringers and ribs to be rotten so I carefully removed them all. I have cut new ones out using 18mm marine ply and the old ones of template. I sanded the entire deck and put another layer of fiberglass down as the hull seamed far to flexible, I also filled the channels in with a few 2" strips as I was advised by others these should be filled. I'm now at the point of installing the new ribs but as this is my first boating project I don't know where to start, firstly what do I use to bond the ribs to the deck, could I use some sort of chopped up fiberglass mat with polyester resin? Sorry if this is very basic it's all new to me! I also aim to keep the cost of this repair as low as possible due to still being at university!
Thanks
James

[camelgas]

I would bed them down on thickened epoxy(peanut butter consistency) and then cover with glass cloth when its gone off.

Leveling them is the tricky bit, I would do the front and back ones first.
When they have dried you can use a long straight edge between them to make sure the ones in between are all the same height, so deck will sit level.

I am just a keen hobbyist not a pro, so there may be a better way.

[JamesGSY]

Thanks for the reply. I just went and brought some epoxy resin and silica powder. So once I've mixed some up and stuck the ribs in should I fiberglass up the sides of the ribs say halfway up and onto the deck or would you go all over the top of the rib too so one big piece of fiberglass?
Thanks for your help
James

[Bigtalljv]

Sounds like good advice to me. There is lots of good boat building advice at www.bateau2.com. It's where I got all my instruction. They have some how to's on stringers and tabbing them in

Jason

[camelgas]

I believe the correct way is to fully encapsulate them with glass cloth/strip.

If you look on you tube there is a guy called frisco boater who posted loads of vids of a deck rebuild, you might find this helpful.

[gtflash]

If you are using epoxy and are going to bed them down then wait, ensure you create a nice soft transition or fillet where the bedding mix meets the stringer and use peel ply. Epoxy blushes when curing and leaves a waxy substance that needs washing off, before epoxy will stick to itself. So if you bed it down and don't encapsulate the wood you might then get the wood wet.

I prefer bedding down and filleting with a smooth spoon to fill all the gaps, then let it get a bit tacky and lay the cloth down while it's still tacky but won't change shape much but before it has cured. Then it's done in one.

I am wondering if you are asking how to bond the ribs to hull or deck on top of the ribs/stringers?

[Ian M]

Got to ask; why are you using epoxy and not polyester resin? There are a few disadvantages with epoxy, not least the price (unless you already have some!).
Whatever you use, make sure to have a nice rounded section to the upper corners/edges of your stringers, so that the matting that you use to enclose them is able to adhere to the stringers without air gaps. Use a serrated roller to bed the matting down when it is wet and to roll out any little air pockets.
Ah, just read your previous posts again, and you mention both polyester resin and epoxy. It is not a good idea to mix them. Bed the stringers down on two or threes layers of matting which has been reasonably well wetted and then fully enclose the stringers in the same matting/resin. Do not use too much resin, the strength is in the matting.