Wooden wood

[Felix]

Sounds like you need to improve ventilation in that room. Or investigate what materials etc. are used to construct saunas.

It was the ceiling of my camperbus.

[mangocrazy]

Sounds like you need to improve ventilation in that room. Or investigate what materials etc. are used to construct saunas.

It was the ceiling of my camperbus.

That's a pretty extreme usage for wooden panelling. Extremes of hot and cold, plus condensation.

[Felix]

That's a pretty extreme usage for wooden panelling. Extremes of hot and cold, plus condensation.

I know others what have been fine with the same stuff. I am putting a new ceiling up after the Christmas and new year. Flexible ply covered in expedition carpet

[Horse]

Sounds like you need to improve ventilation in that room. Or investigate what materials etc. are used to construct saunas.

It was the ceiling of my camperbus.

Half the story again

Still the same problem and, potentially, the same solution. The wood doesn't know where you're using it

Although, presumably, made worse by cooking and just being in there and breathing. So you need improved ventilation for the living space. And, potentially, between the roof and lining.

[Horse]

That's a pretty extreme usage for wooden panelling. Extremes of hot and cold, plus condensation.

I know others what have been fine with the same stuff. I am putting a new ceiling up after the Christmas and new year. Flexible ply covered in expedition carpet

Aling with ventilation, how about insulation between the roof and lining? If the ceiling is warmer you might get less condensation.

[Felix]

Aling with ventilation, how about insulation between the roof and lining? If the ceiling is warmer you might get less condensation.

Bubble foil on a fiberglass roof. It was an LDV convoy, plenty ventilation holes

[Horse]

It was an LDV convoy, plenty ventilation holes

In that case, you need a dehumidifier!

[ZRX61]

We get a plywood version here called beadboard.

[Yambo]

Or investigate what materials etc. are used to construct saunas.

There's lots of different varieties of wood. Knowing which one is best for any particular application is part of being a good carpenter/woodworker.

Wood butchers like me use what's to hand, or plywood and slap a coat of epoxy on it.

[mangocrazy]

Wood butchers like me use what's to hand, or plywood and slap a coat of epoxy on it.

Would sufficient coats of epoxy render the wood underneath fully waterproof? I'm toying with making a big photographic darkroom sink out of plywood, with loads of coats of epoxy on top. Is this viable?

[Mr. Dazzle]

Glass fibre boat hulls are about half epoxy*! Should provide some reassurance of its water integrity.

*or maybe Polyester

[Yambo]

Wood butchers like me use what's to hand, or plywood and slap a coat of epoxy on it.

Would sufficient coats of epoxy render the wood underneath fully waterproof? I'm toying with making a big photographic darkroom sink out of plywood, with loads of coats of epoxy on top. Is this viable?

Mmmm, sufficient . . .

I have a rowing boat and two kayaks made out of plywood. The plywood is covered with fibreglass which is bonded to the wood with epoxy. All the seams are bonded with thickened epoxy. On top of the fibreglass is 3 or 4 coats of epoxy but this is mainly to fill the weave of the fibreglass to make a nice smooth finish.

I've recently femoved the fibreglass from the deck of one of the kayaks, it was starting to delamination in a couple of places, and I'm not replacing it, just painting the deck with an epoxy barrier coat - paint basically.

A couple of coats of epoxy will certainly seal the wood but you'd need more coats on end grain and the faces may absorb the epoxy more in some places than others. That was the issue with my kayak deck and I probably neglected to wet the surface with epoxy before applying the fibreglass.

Epoxy is ace stuff, not cheap though and as I said, the wood itself may be the problem and may require more coats to do the job you want. Epoxy is not UV resistant so outside use will require some top surface coating to prevent the epoxy degrading.

Basically though, epoxy, as a coating is brilliant. Sufficient depends on the surface being treated.

[mangocrazy]

"sufficient" = 'how long is a piece of string'. then...

My intended usage would be inside, in a darkroom, so minimal amounts of UV. Usage would be periodic, but when it was being used it would be for several hours on end, anywhere up to 10-12 hours. Chemicals used are basic photographic chemicals, so a mixture of fairly dilute acids and alkalis, with good likelihood of staining (photographic developer goes orange/red as it ages/oxidises) but contact will only be for hours, not days. The main requirement is to support dishes of photographic chemicals as a succession of prints are made with the prints passing through 3 or 4 dishes as they go through the process. Once the session is over, the whole sink will be thoroughly washed down and rinsed.

It is possible to buy ready made fibreglass or stainless (!) tanks, but they are very spendy (esp. stainless) and I've heard of a lot of people just making a big sink/tray out of plywood and then covering the ply with a) several coats of epoxy or b) fibreglass followed by epoxy. Obviously option b would be more resistant, but it also greatly increases the time, expense and faff-factor. Hence why I'm wondering if multiple coats of epoxy on 18mm ply would suffice...

[Treadeager]

@mangocrazy Tried eBay for reclaimed butler sinks ?

[mangocrazy]

@mangocrazy Tried eBay for reclaimed butler sinks ?

Nice idea, but I need something that will take at least 3 (preferably 4) 20" x 16" photographic trays/dishes. That requires a minimum length of 6 feet, and preferably closer to 8 feet.

I can only begin to imagine the weight of a butler/belfast sink of that length...

[Taipan]

@mangocrazy Tried eBay for reclaimed butler sinks ?

Nice idea, but I need something that will take at least 3 (preferably 4) 20" x 16" photographic trays/dishes. That requires a minimum length of 6 feet, and preferably closer to 8 feet.

I can only begin to imagine the weight of a butler/belfast sink of that length...

Have you looked at plastic, farm animal feed trays?

[mangocrazy]

@mangocrazy Tried eBay for reclaimed butler sinks ?

Nice idea, but I need something that will take at least 3 (preferably 4) 20" x 16" photographic trays/dishes. That requires a minimum length of 6 feet, and preferably closer to 8 feet.

I can only begin to imagine the weight of a butler/belfast sink of that length...

Have you looked at plastic, farm animal feed trays?

The only ones I can see are not water tight - they're made of steel panels bolted together. I really need a single piece structure (preferably plastic, for manageable weight). I'll keep looking though...

[mangocrazy]

This is the kind of thing I'd want to replicate. In an ideal world I'd just order the larger of the two sizes, but the cost (£668) is a trifle daunting...

https://www.theimagingwarehouse.com/Pro ... room-Sinks

[Yambo]

The main requirement is to support dishes of photographic chemicals as a succession of prints are made with the prints passing through 3 or 4 dishes as they go through the process. Once the session is over, the whole sink will be thoroughly washed down and rinsed.

Personally I'd make your long sink thingy out of one sheet of plywood. cut the pieces, put it all together, fillet the inside seams with thickened epoxy then something like 6oz fibreglass on the inside while the filleted seams are still wet. When that's all set up (24 hours or so) another couple of coats of epoxy all over the inside. Tutorials here: https://www.clcboats.com/shoptips/

Epoxy is pretty resilient to a lot of chemicals in my experience (although I haven't tried 'em all ). If you shape the panels right it could double as a small boat.

An easy peasy project, it'll take 4 days maximum (it's best to let the epoxy set up over 24 hours. You could save some money by using polyester resin instead of epoxy. Most shop built fibreglass boats are made with polyester resin. You just have to be careful with the hardener, MEKp as you only need about 2% or 3% hardener to resin ratio (3% will go hard faster) and MEKp is quite a nasty chemical. I measure small quantities with disposable syringes.

Also, have a look at Andy's YouTube videos on Boatworks Today, he's a dab hand at this sort of thing.

[Horse]

The only ones I can see are not water tight - they're made of steel panels bolted together. I

Get that welded up?