I’m curious to know how moisture-resistant Magnalac and other pre-catalyzed lacquers are compared to oil-based polyurethane.
My wife and I are designing cabinets to display her orchids so I need something to seal the wood that can handle high humidity and some direct moisture.
I have built similar cabinets in the past and have either used oil-based poly or Envirotex Lite, a solvent free epoxy.
Oil-based poly is not as moisture resistant as we’d like. The Envirotex is great but expensive. Hoping something like Magnlac will be a bit cheaper than the epoxy but offer better protection than the oil-based poly.
Any thoughts on Magnalac or other pre-catalyzed lacquers?
Replies
Chris,
Cat-lacquers like Magnalac and Magnamax are not going to please you if the OB poly didn't perform well enough for your purposes.
We could go into a long discussion of the properties of various finishes and why they might or why they won't meet your needs, but the bottom line is that you're probably already using an appropriate material.
There are numerous other finishes out there you could try, but many of those that will perform better than off-the-shelf OB polys and such...... are only available in 5 gallon quantities. Same is true for Magnalac and Magnamax around these parts. While you experiment with these other finishes, you're consuming time and dollars. If they fail to cut the mustard, all that money and time is a waste. Then you can take more money and go buy what does work.
Campbell's offers other conversion finishes that may cut it, but no guarantees.
http://www.mlcampbell.com/pages/family.asp?fam=CLR
(You'll note that Magnalac and Magnamax make no special mention of water resistance while some of the other products do. There's a reason for this.)
A high quality marine varnish just might serve you. I'd think it worth a try and those you can buy in gallons. The brands to look for are Interlux, Woolsey, Pettit or Epifanes. Be sure to follow directions as to surface preparation and number of coats. 5 or 6 coats as a rule. This stuff is pricey, too. Zero gain perhaps on cost compared to what you're currently using.
I'd also give good odds to the products from West Systems. Epoxy again. :-)
http://www.westsystem.com/
Edit: Conversion finishes must be sprayed. If you don't have the capabilities to do this or are willing to pay someone to do it for you........don't bother looking into any of them as a potential.
Knowledge is power, but only if applied in a timely fashion.
Edited 5/7/2005 10:25 pm ET by GOLDHILLER
I can buy small quantities of Magnalac in pre-packaged spray canisters from a local paint shop. It ups the price a bit but I can experiment for about $15 and get 2 coats on 32 sq. feet. But if Magnalac is only marginally better than readily available polys (Minwax, Varathane) I won't bother. I have heard of people using it sucessfully in plant terraria but the same people have had decent luck with oil-based poly. I want something more durable.Marine varnishes don't sound like they'd offer me any advantage. I don't need their flexibility or UV absorbers anyways, not to mention I don't care to deal with the extended offgas time.I have heard a lot of good things about West Systems. In fact I know it's been used in projects identical to what we're starting.Do you know what kind of coverage I can expect per gallon? Is West Systems solvent based?What I'm really hoping for is something a bit cheaper than Envirotex and with the ease of application of Magnalac.
You may know something more than me, but Im with Goldhiller. Ive used Epifanes Spar on a ton of projects from Yachts topside to garden benches. Im not aware of offgas being much different than your Oil Poly.
If done properly you do have to juggle cutting the coats at varried percentages, but its worth the effort. If UV isnt an issue, that just makes the finish that much more of a benifit, because the effect of the sun is the first thing to damage spar.
-zen
If you pop those links, you'll find much info about the available products.The Krystal product from Campbell sounds very promising if you want ease of application, fast dry and cure, clarity, non-yellowing and yet high resistance to humidity and droplets...but don't need the extra flexibililty of a long-oil and are concerned about off-gassing times. Perhaps this same paint shop can get you a small aerosol can of the Krystal.Sherwin-Williams also offers quality products of this nature and a chat with their store representative or bettter yet, the tech guys at the company should help narrow down which of these products if any, is most apt to meet your desired price, ease of application, etc.The West System links should answer most any question you might have concerning that family of products. Click on the product guide and you'll see that the 207 hardener is likely what you would want. There will be a slight amber cast involved and if you don't want that, you might be best off using the Enviro products that seemed to meet to your needs and desires. Coverage is pretty difficult, if not impossible to call. Depends upon your desired final film thickness, etc.Knowledge is power, but only if applied in a timely fashion.