Where should I put glass on a flat surface? (& why?)

[Fisherball]

Maybe a dumb question but why put glass on a flat, supported surface of plywood that's sealed with resin? Just curious because I know structurally the plywood will deal with the weight on it. I'm planning on building a live well from plywood, sealed with resin & glassed over inside, especially corners, where I will fill with a wood flour/resin mix. Should I glass over top & outside of sides? It will sit on a casting deck I am adding over the front seats of my tri-hull bowrider but the top will probably be stood on occasionally. Should I also glass the casting deck?

 

[scipper77]

Re: Where should I put glass on a flat surface? (& why?)

If you glass the inside top and outside then do you need the wood??

 

[Fisherball]

Re: Where should I put glass on a flat surface? (& why?)

Without the wood it would be too flexible!

 

[tallcanadian]

Re: Where should I put glass on a flat surface? (& why?)

The fiberglass will give you the strength and protection needed. Not sure what kind of resin your using but if your going that route it would be just as easy to put some glass with it, make it stronger and never, ever rot.

 

[Fisherball]

Re: Where should I put glass on a flat surface? (& why?)

Thanks! I know glasss won't help keep water out but if it'll add strength & protect it's surface better than that's what I'll do. Don't know about resin yet, this is in early planning stage. Waiting for the $$$ & the economy!

 

[ondarvr]

Re: Where should I put glass on a flat surface? (& why?)

Resin by itself has little strength (either type), so it will normally crack when subjected to any stress. Polyester will fail before epoxy, but they both will over time.

 

[tallcanadian]

Re: Where should I put glass on a flat surface? (& why?)

Not sure what you mean by 'not' keeping water out. That's the whole idea of fiberglassing, to keep water out. After all, your boat is made of fiberglass. Keeps water out.

 

[rich158]

Re: Where should I put glass on a flat surface? (& why?)

Maybe a dumb question but why put glass on a flat, supported surface of plywood that's sealed with resin? Just curious because I know structurally the plywood will deal with the weight on it. I'm planning on building a live well from plywood, sealed with resin & glassed over inside, especially corners, where I will fill with a wood flour/resin mix. Should I glass over top & outside of sides? It will sit on a casting deck I am adding over the front seats of my tri-hull bowrider but the top will probably be stood on occasionally. Should I also glass the casting deck?

put simply: yes, glass it.

if you do not glass it, the epoxy surface will start micro-cracks within a couple of years & the job will need doing again as water will get in. You can get away with a single layer of epoxy & fibreglass cloth underneath but use 2 layers of cloth (or 1 light layer of CSM with a surface of cloth) and epoxy on the top and sides.

For the sake of $30-50? in materials plus maybe an hour of work. It'll be bullet proof & look good.

*** presume you are using epoxy.*** poly would work if you are bonding to a surface that does not already have epoxy on it. Definitely use CSM + cloth with poly resin. poly is much cheaper but not quite as waterproof so you'll need the CSM layer to guarantee no moisture will ever reach the ply.

 

[Fisherball]

Re: Where should I put glass on a flat surface? (& why?)

Cool, those are the answers I was looking for. By not keeping the water out I meant the glass itself is not waterproof, with the resin on it it is. I didn't realize that the glass was needed to keep the resin from cracking. That makes sense. I always like to know why something works. I'll spend the $$ to make it last, putting as many layers of each as it takes.