chemical resistance

[olleorama]

How would the following materials/coatings resist the corrosiveness of photo chemicals?

Urethane alkyd?

Polyester?

Epoxy resins?

Which would be have the best resistance?

[Bob-D659]

What are you coating and what type of finish do you want? Are you looking for resistance to working solutions, or to concentrated solutions of NaOH. Epoxies are the most durable and the easiest to DIY by brush if you aren't too concerned about the look of the final finish.

[olleorama]

Originally Posted by Bob-D659

What are you coating and what type of finish do you want? Are you looking for resistance to working solutions, or to concentrated solutions of NaOH. Epoxies are the most durable and the easiest to DIY by brush if you aren't too concerned about the look of the final finish.

Working solutions, B&W print chemistry.

[Bob-D659]

Ok, what are you coating, glass, copper, brass, 302L, 316 or 1010 steel?

[olleorama]

Originally Posted by Bob-D659

Ok, what are you coating, glass, copper, brass, 302L, 316 or 1010 steel?

Whatever will turn out to be cheapest. I may even go so low as particle board.

[David Brown]

You must be building a sink. DO NOT use particle board. or MDF. You will be sorry later.

[olleorama]

Originally Posted by David Brown

You must be building a sink. DO NOT use particle board. or MDF. You will be sorry later.

Hmm, even if I coat the whole area (and the cuts) with polyester or epoxy? Would seem as it could be treated as being made from plastic if it were coated that way. I've seen wooden ships made from plywood coated in polyester and they seem quite fine after decades in marine environments. Although photo chemicals is probably a lot more corrosive than ocean water.

Personal experience?

I'm not really planning anything, just thinking in budget restricted ways. Second hand SS sinks and the likes are not really viable this time, unfortunately.

[Ian Grant]

Of course wood can be fully treated and made waterproof and coated, MDF should work perfectly but marine ply is possibly better. There are books and articles on how to do it.

Personally I'd line a wooden sink with thin PVC sheet and weld or solvent cement it's seams, I made a lot of things that way in the past.

Ian

[David Brown]

Originally Posted by olleorama

I've seen wooden ships made from plywood coated in polyester and they seem quite fine after decades in marine environments. Although photo chemicals is probably a lot more corrosive than ocean water.

Personal experience?

Yes. Although not with a sink, but other applications. There is plywood made for outdoor and marine purposes. Wood in boats and ships is specially treated, etc. Particle board and MDF are not and will disintegrate if it gets wet. It will fail. I am not disputing that it could probably be coated with enough plastic or other material to make it initially water proof, but if the protection gets a break in it, and the particle board does get moisture, it will swell up and begin to come apart. By the time one puts enough effort and expense into making a water proof wooden sink (or boat), it would not be much more expense to simply use a proper wood substrate in the first place. Just my opinion, of course ...

[Ian Grant]

David, MDF is treated unlike chip board (particle board) so has very significantly better water resistance which is major a reason for it's popularity.

Ian