GRP Help: Reglassing the Deck of a Searider 5.4m - What Resin etc?

[Catamaran]

Hi All,

Got a bit of a winter project to crack on with...

Got basically given a Searider 5.4 and a new console. Someone had cut the old one out, back to the plywood deck, so I'm left with a roughly 1.5 x 0.5m hole in the GRP/gelcoat that shows bare plywood.

It's all nice and dry in a barn, so I'd like to get it sealed up and ready to put the console back on. I've never done fibreglassing before, so I'm going to have a practice on some old plywood bits, first.

Questions...

1. What resin do I need? Epoxy or polyester?
2. I'm going to glass in a new piece of ply, to raise up the deck to let me bolt the console down. Do I put glass matting between the deck ply and the new ply? Or glue the new ply to the old? The old is a bit rough, but is very solid.
3. What colour of orange top coat do I need to finish the job off? And can I do the whole deck in it, to match it all up? (If I can do the lot, I might change the colour.)

Thanks in advance...

 

[Poignard]

This is similar to the work I did re-sheathing the ply coachroof of my boat.

I used epoxy and followed the clear and detailed instructions in the WEST epoxy manual, which explain it far better than I could.

http://www.robbins.co.uk/Pdf Files/sheathing_guide.pdf

 

[Stemar]

I'd use epoxy too, you'll get a better bond to old GRP than with polyester. A coat of epoxy to soak the wood, then build up with glass cloth - not chopped strand mat, which has a solvent(?) in it to help it bond with polyester, but interferes with bonding with epoxy, but read the guide first.

I'm not altogether clear where the new bit of ply is going and why, but you don't want a gap between the two layers of ply, or damp will get in and rot everything. Maybe epoxy it down in the hole and glass over everything?

Finally, unless you're both skilled and lucky, you won't match the orange paint (is it paint or a dye in the gelcoat?), so I'd be inclined to redo the whole thing with a 2 pack paint. Consider that, if you change colours, any inevitable scratches will scream out their presence as orange against whatever colour you choose. An orange scratch in orange paint won't be nearly so visible.

 

[DownWest]

Def epoxy, but the problem with chopped strand mat is that it held together with a binder, which polyester dissolves, allowing it follow double curves etc. Epoxy does not dissolve it. But it doesn't sound like you need to worry about curves, so woven cloth is the best. Ply to ply, glue it with thickened epoxy.
As above, the West book explains all. But there are far cheaper resins about. Also, you will need to keep things a bit warm. 15°C works. So a tent and an electric heater. For something flat, an electric blanket with another old blanket on top works. Bit of plastic under so it doesn't stick to the work.

 

[Catamaran]

Thanks guys... what about the topcoat? Do I just go for it and overpaint the whole lot.

Btw the new layer of ply is for the console to be bolted to, so I don’t have to drill the original deck.

 

[bernie_ni]

If you are using epoxy, the same suppliers should stock csm that is soluble with epoxy. It is stuff designed to be used with epoxy and is worked just the same way as the polyester stuff

 

[ShinyShoe]

This needs a picture.

Not convinced you have a hole in the ply rather a hole in the GRP over the ply.

The general view is that glassing down the console is best... better than screwing down. So no need to screw. . .

Top coat - provided it hasn't been painted - flow coat is what you want.

 

[lw395]

struggling to picture the arrangement here.
Epoxy is costly.
I might be looking at glassing over the old ply and glassing the console down. Why bolts?
You might be better with a heavier layup of polyester.
Consoles need to be properly strong, there have been bad accidents where they break free and a SR5.4 will bash into waves hard and fast. 2 or 3 people on a jockey seat, that's a lot of impact.
I'd do a bit of estimating, area and thickness of layup, kgs of resin etc.
Any ply needs to be very well sealed, if the bolts move it may leak.

 

[Catamaran]

Thanks for the replies guys...

This needs a picture.

Not convinced you have a hole in the ply rather a hole in the GRP over the ply.

The general view is that glassing down the console is best... better than screwing down. So no need to screw. . .

Top coat - provided it hasn't been painted - flow coat is what you want.

I'll try for a picture... just not had chance to get to the barn where it's kept. Yes, it's a hole in the GRP rather than the ply.

The original console was well bolted to a raised piece of ply, which I've seen on a few SR5.4s. I was going to follow a similar pattern with the new console, which is a console off a SR4.7 and was bolted to that!

The setup was that the bolts were passed through the ply, leaving the thread sticking up, then these were glassed in waterproof and the console bolted down to them. Pics will be easier!

Anyway, the reason I'm asking all these questions now is that I'm hoping to collect everything over the next coupe of weeks and get the job done before winter really sets in. If nothing else, I'd like to get the plywood sealed, so I;m not fretting about any rain hitting it and meaning I've got ages to wait for it to dry out!

 

[lw395]

If the console is designed to be bolted down, that has advantages. You might one day want to remove it to change steering or something. Or depending on how the boat is used, people want the console further back or forwards.
I've seen too many that are just held down with a few tappers through a thin grp flange though!
Also are you aiming to have the console watertight at deck level or not?
Waterproof is nice, free draining is OK, 'leaky' is a pest IMHO.