I can source 105 and 205 locally, does the 205 faster curing works as good as the 206 ?
Shellac is kind of hard to get here (CZ), but I found some. It is the stuff used for violins amd similar instruments. Am I right?
I think water-based polyurethane has replaced shellac as a wood sealer in most professional applications. Any business which must be VOC compliant, and in the US that would be literally "any business", would have a hard time using solvent based shellac.
Having used water-based polyurethane, I think it makes an excellent sanding sealer.
Having used water-based polyurethane, I think it makes an excellent sanding sealer.
I understood that water based anything might be bad news for mdf, the reason I looked for solvent based primers.
I can find locally water based epoxy, polyurethane and acrylics, like Zinsser 123 (can’t find b-i-n) or Varathane sanding sealer. Would these work with mdf?
I just finished fabrication and painting of my new TV/stereo bench, one rattle can of automotive 2K filler, it really can't be any easier (if you have a ventilated area to paint in). Just make sure to look at the edges, you might have to let the first layer cure to be sanded lightly before you lay down the final coats (as long as the can stays somewhat cold you'll have almost a day to use it).
To paint MDF, you need a primer of sorts, apply in a thin coat, let it dry thoroughly and sand it with something like 180 grain.
Apply a second coat and resand it, with a 240 grain. Be careful, and control the surface by the touch. Then apply a third coat for a nice finish. Usually, this gives you good results.
If you're after a high-gloss finish, I'd recommend 3 thin coats before the final varnish...
Apply a second coat and resand it, with a 240 grain. Be careful, and control the surface by the touch. Then apply a third coat for a nice finish. Usually, this gives you good results.
If you're after a high-gloss finish, I'd recommend 3 thin coats before the final varnish...
Or, there’s pre-coated MDF with a priming film…
https://nl.kronospan-express.com/en...ie-0004/mdf-with-priming-film-0004-721#c=1331
https://nl.kronospan-express.com/en...ie-0004/mdf-with-priming-film-0004-721#c=1331
I've used 105 to seal MDF cabinets before, worked perfectly but isn't the cheapest option and leads to a more uneven layer than other sealers so requires more sanding. As far as I'm aware 205 and 206 can be used interchangeably. I use 206 if it's hot (>25*C ambient), 205 if it's cool.
Worth noting that epoxy does not sand as easily as other sealers and tends to clog up sandpaper particularly if you use power tools to sand it. It may take weeks to cure glass hard in cold temperatures. It's also necessary to sand epoxy before applying another layer of epoxy or some other coating, due to amine blush.
Hmm, at this point, I'd opt for a thinner panel of HDF since it's considerably stiffer/stable than MDF and needs no sealing.
If you are in Australia I can't think of any reason to use West Systems epoxy. Boat Coat epoxy does not suffer from amine blush, and is far less toxic. It also can be used with a preservative (supplied by the same company) that causes the epoxy to penetrate better. Usually you use it with the preservative for the first coat only. Of course you don't need it to preserve the wood (or mdf), but it is useful to improve penetration. I have used it on boats and music instruments in the first coat. I have also used West Systems, which also works well, but some people do develop fairly severe allergies to West Systems epoxy. I have not heard of any one developing severe allergy to Boat Coat epoxy, however you still need to take precautions not to get it on your skin or breath the fumes. Boat Coat also manufacture an excellent epoxy glue that has a 1/1 mixing ratio and comes in various colours or can be coloured with colouring supplied by the same company that makes the epoxy. Best epoxy glue I have used to date, easy to mix and the shelf life is unlimited. Shelf life of West Systems is not unlimited, although it still works after a few years but the fumes of the hardner are awful and get worse with age.
Are you referring to Bote-Cote Epoxy? Found it on eh-bay, maybe they'll ship overseas. Don't need much but I just might find other usage for it, like renewing home main entrance wooden door. Non-water based primer is none to be found locally
I want to +1 the Zinnser BIN shellac primer for MDF, including machined edges. It really seals it up and takes paint well. I do a few coats with light sanding in between.
Good thread with lots of insights for a first time finisher to be 😛. I’ve built an enclosure with what seems to be a low grade 27mm mdf. The edges at a cross section are stiff but core middle material is pretty porous that I can push a bit of air blowing with my mouth if trying to see if it’s air tight. I had in the past built with denovo cabinet kits, thinner mdf but was quite air tight for its entire thickness. Need to pay attention to well sealing the enclosure, I live in a pretty humid environment.
Seems the options for me are:
1. Zinsser BIN (order overseas)
2. West systems epoxy 105 & 205, wait a bit for cooler ambient
Seems the options for me are:
1. Zinsser BIN (order overseas)
2. West systems epoxy 105 & 205, wait a bit for cooler ambient
Is there a reason why epoxy is preferred over a normal sanding sealer? I work with epoxy a lot, mostly on boats. It is a pain compared to a one-part clear finish or primer.
I have used both (laminating) epoxy and polyester and I see no other benefits than when I want to air seal or stiffen up (adding fiberglass) the mdf.
It's a pain in the behind to sand smooth compared to an automotive 2K primer (and need longer to fully cure), to get it perfect you would almost have to use it anyway (at least that's what I've done if I paint).
But each to their own.
It's a pain in the behind to sand smooth compared to an automotive 2K primer (and need longer to fully cure), to get it perfect you would almost have to use it anyway (at least that's what I've done if I paint).
But each to their own.