Everlasting paint

[Rory Fields]

I unwittingly bought a load of crownboards a while back where the battens on the top and bottom provide beespace but the cut plywood edge is entirely bare, sandwiched in between. I'm a bit obsessive about doing a job once rather than having to repeat it every year so I was wondering which paint would do the job of sealing the edge for as long as possible please? Previous experience of yacht varnish on wood hasn't lasted more than a couple of seasons in the sun so I was assuming gloss or some matt would be best, but I'm money poor and time rich, so not looking for Farrow and Ball nor bothered about colour particularly. I'm afraid I know nothing about paint, despite my town having been built on the stuff. Thanks for any guidance, as ever, and merry Xmas everyone! Cheers, Ror

 

[Garry R]

Ronseal woodstain is pretty good ad easy to apply

 

[ericbeaumont]

nor bothered about colour particularly

Get hold of oil-based paint; thin it a little and let several coats soak into the ply; finish with a thick coat or two. If you had time and not too many boards, put a little paint in a tray or trough and add a stack of boards; rotate after a while. Buy bargain end of line paint, sales paint, or scrap paint.

 

[Murox]

Thinned out oil based paint as @ erichbeaumont suggested should work well. I once treated a set homemade wooden trailer sides that way, made from pine. 18years later they still haven't rotted and actually don't look too bad either. The important thing was that the wood was really bone dry beforehand, it just 'sucked' the thin paint layers in.

 

[robmort]

Not sure why you need to seal them; the crownboard is kept dry under the roof. If it's marine ply it won't rot or split in any case. Why seal only the edge and not the rest of it If it's likely to get wet?

 

[JamezF]

Not sure why you need to seal them; the crownboard is kept dry under the roof.

That's generally my approach. If something is liable to get wet and stay wet for any extended period (a Demaree board, for instance) then I'd certainly look to seal it. For something that's hidden under the roof I'd really not stress about it.

James

 

[drex]

I don't even bother to paint things like Demaree boards, as they are not in for that long, and over summer anyway. Certainly a crownboard under the roof needs no protection

 

[JamezF]

I don't even bother to paint things like Demaree boards, as they are not in for that long, and over summer anyway. Certainly a crownboard under the roof needs no protection

Yeah, but it only rains by appointment in the South Hams. Here it can go on for weeks non-stop

James

 

[E&MBees]

Yeah, but it only rains by appointment in the South Hams. Here it can go on for weeks non-stop

James

It must have changed then. When I lived in the South Hams, it rained whenever it fancied. Generally when the school bus was late!

 

[ericbeaumont]

crownboard is kept dry under the roof

A crownboard is a versatile tool and when used as a floor or split board it is open to the elements, so sealing is a good decision.

marine ply it won't rot or split in any case

Marine ply is a quality ply but certainly not waterproof and only as good as the waterproof glue; the ply will certainly delaminate in time and sealing is a good decision.

 

[Rory Fields]

Ronseal woodstain is pretty good ad easy to apply

would moisture not make short work of even stained ply? Was assuming it'd need to be a paint of some description but absolutely naive about such things. I actually feel nostalgic for creosote, minus the carcinogenic qualities!

 

[Rory Fields]

Not sure why you need to seal them; the crownboard is kept dry under the roof. If it's marine ply it won't rot or split in any case. Why seal only the edge and not the rest of it If it's likely to get wet?

It's not marine ply; I'm as bothered about it warping in my shed as about getting wet on the hive tbh, I'm a bit of a fanny and I just worry about not looking after stuff Some of the ones I had on (under deep roofs too) seem to have somehow sucked moisture in and started to warp or delaminate - not sure if it's reflective of the quality of ply or what, as the relevant hives are all in full light at the top of a hill with trees sheltering them from the north.

 

[Rory Fields]

I don't even bother to paint things like Demaree boards, as they are not in for that long, and over summer anyway. Certainly a crownboard under the roof needs no protection

Come to south-west Northumberland - we get the rain at the top of the Pennines. Willie Robson, not knowing I lived here, mentioned my town as a 'bloody bad place to keep bees', but we've got what we've got

 

[drex]

@Rory . Are your roofs watertight? Do you have insulation under the roof? Is ventilation adequate, or the colony small?

 

[Garry R]

would moisture not make short work of even stained ply? Was assuming it'd need to be a paint of some description but absolutely naive about such things. I actually feel nostalgic for creosote, minus the carcinogenic qualities!

Ronseal woodstain is more of a varnish rather than stain

https://www.screwfix.com/p/ronseal-...H61g0KGIb3G3WENUppcaAvV4EALw_wcB&gclsrc=aw.ds

 

[ericbeaumont]

would moisture not make short work of even stained ply?

woodstain is more of a varnish rather than stain

Yes, stain is stain and an oil-based paint or sealant, enough to creep deep into the ply, will give you the result you seek: protection from damp, upswept rain, Northumberland damp, a damp shed, or any other sort of damp that creeps up.

 

[pargyle]

Come to south-west Northumberland - we get the rain at the top of the Pennines. Willie Robson, not knowing I lived here, mentioned my town as a 'bloody bad place to keep bees', but we've got what we've got

The problem with any sort plywood (other than marine ply) is that, even if you treat the cut edges, moisture will find its way into the laminate and the glues they use on cheap plywood isn't in any way water resistant. It will delaminate ...

From past experience :

1. If it is the cheap plywood that there are obvious voids in the cut edges you need to fill them - epoxy (car body) filler is best.

2. Rub them down so the edges are smooth - any fibres standing up (no matter how small) will wick moisture in to the laminated veneers.

3. Polyurethane paint is pretty much impermeable or two pack epoxy floor paint. (watch out for it in the reduced to clear section in your local B & Q - it's not cheap - ask on freecycle if anyone has any leftovers). Paint the cut edges properly - two thin coats are better than one thick one.

4. When it's dry - cover the edges you have painted with aluminium tape - cheap as chips from Toolstation. That will stop the edge delamination for a good few years but, if it is cheap softwood ply then you also need to paint the faces of the boards as well. Any oil based paint will work - you can also paint over the aluminium tape. The tape sticks to any surface and you can patch repair any that gets knocked and damaged. It's pretty much waterproof with a coat of paint on top.

Belt, braces and a piece of string but ... if you want it to last you have to put the work in. I always buy any heavily reduced decent paint I come across (the colours are not important) for jobs like this. Warped crownboards are useless and delaminated edges are a haven for creepy crawlies. You can make a silk purse out of a sow's ear but, in many respects, it's better not to start off with a sow's ear !

 

[jenkinsbrynmair]

I've always considered thin ply crownboards to be an expendable commodity and have never bothered pampering them or worried about water damage etc. saying that, I still have every crownboard I've ever had/made, some are a bit tired now but still usable.
Warping is the biggest issue - but ply will warb in a nice dry environment as much as a damp one. I find the best solution is to leave them out on the lawn, in the rain for a day or two