Waterproofing marineply

[Mitch3]

We are currently having new deck boards cut using marine-ply for our dilapidated springer. I have been advised to use 'fibreglass resin' to waterproof the edges, then primer, undercoat and varnish on top. I am however, a little confused by the vast array of fibreglass resins on the market and none seem to be for the purpose of waterproofing marine-ply? Any advice would be very much appreciated.

[larkshall]

Hello, and welcome to the madhouse (forum).

 

Use any clear fibreglas resin and hardner mix. Don't forget marineply is often incorporated into GRP boats for structural strength, eg transoms, roof panels, bulkheads etc.

[RobinJ]

We are currently having new deck boards cut using marine-ply for our dilapidated springer. I have been advised to use 'fibreglass resin' to waterproof the edges, then primer, undercoat and varnish on top. I am however, a little confused by the vast array of fibreglass resins on the market and none seem to be for the purpose of waterproofing marine-ply? Any advice would be very much appreciated.

If you are planning to cover with fubreglass, then fibreglass resin makes sense!

Expoxy resin is probably best for just sealing edges?

My preference would be to egde with wood, either lipped or biscuit jointed using a suitable waterproof glue!

Good yacht varnish after staining, why prime and undercoat?

[BEngo]

We are currently having new deck boards cut using marine-ply for our dilapidated springer. I have been advised to use 'fibreglass resin' to waterproof the edges, then primer, undercoat and varnish on top. I am however, a little confused by the vast array of fibreglass resins on the market and none seem to be for the purpose of waterproofing marine-ply? Any advice would be very much appreciated.

 

 

The choice is generally between polyester and epoxy resin

 

Some polyester resins absorb water. The best marine resin is probably the epoxy resin to be found in the WEST system. UK dealers.

Other resins at Glasplies

 

No connection with WEST or any of these. I believe Alnwick may have used the WEST stuff and I have used Glasplies but not for some years.

 

An alternative to marine ply deck boards is hexagrip (or similar) - a phenolic faced ply so no painting, and very hard wearing, but you still need to seal the edges.

 

N

[smileypete]

We are currently having new deck boards cut using marine-ply for our dilapidated springer. I have been advised to use 'fibreglass resin' to waterproof the edges, then primer, undercoat and varnish on top. I am however, a little confused by the vast array of fibreglass resins on the market and none seem to be for the purpose of waterproofing marine-ply? Any advice would be very much appreciated.

Best way to make it last is soak the edges overnight in wood preserver, improvise a trough out of thick polythene and some battens.

 

As others say, epoxy is the best resin, but if it gets chipped off try edging the ply with hardwood or even aluminium angle.

 

Do you plan to paint the top or use a protective wood stain?

 

cheers, Pete.

~smpt~

[Mitch3]

Thanks for the responses, all useful. Am onto it now and just waiting for the rain to stop now.

[blackrose]

The choice is generally between polyester and epoxy resin

 

Some polyester resins absorb water. The best marine resin is probably the epoxy resin to be found in the WEST system. UK dealers.

Other resins at Glasplies

 

No connection with WEST or any of these. I believe Alnwick may have used the WEST stuff and I have used Glasplies but not for some years.

 

An alternative to marine ply deck boards is hexagrip (or similar) - a phenolic faced ply so no painting, and very hard wearing, but you still need to seal the edges.

 

N

 

I used the West epoxy resin to seal a ply cover I made for my sliding rear hatch. I couldn't insulate the steel hatch from the inside because there was no clearance, so I decided to insulate it from the outside with foam and then fit a cover. I sealed the ply cover inside and outside with a couple of coats of epoxy and then painted it. 7 years later and there are still no signs of weathering - and it was just exterior ply with pine sides.

 

Edited July 14, 2012 by blackrose

[Mitch3]

Best way to make it last is soak the edges overnight in wood preserver, improvise a trough out of thick polythene and some battens.

 

As others say, epoxy is the best resin, but if it gets chipped off try edging the ply with hardwood or even aluminium angle.

 

Do you plan to paint the top or use a protective wood stain?

 

cheers, Pete.

~smpt~

 

The marine-ply is very thick with a top covering surface which is waterproof and non slip, so thankfully no need to paint, stain or varnish. Thanks for the wood preserver tip though; gonna look into that.

[NB Alnwick]

We are currently having new deck boards cut using marine-ply for our dilapidated springer. I have been advised to use 'fibreglass resin' to waterproof the edges, then primer, undercoat and varnish on top. I am however, a little confused by the vast array of fibreglass resins on the market and none seem to be for the purpose of waterproofing marine-ply? Any advice would be very much appreciated.

 

I was advised by a very well respected boat builder to use two or three coats of West System

 

There is more about West System here:

 

http://www.wessex-resins.com/westsystem/