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from http://www.talkshopbot.com/forum/messages/315/21197.html?1183467462#POST53545 This is just roughly brought over...needs a lot of filtering. Might also have material for a couple of topics.




am making some dry erase marker boards and would like to frame them in baltic birch. So far every one of my clear coats is stained by dry erase markers. Anyone know of anything clear that would work? I've tried spar poly, polycrylic, deft lacquer and krylon uv clear.

  • I have used Gemini conversion varnish (product #550-0012) for quite a few years and it's pretty impervious to most anything once it's cured. It is a high solid/build finish that has to be catalyzed before use.

I just tried a marker on it and it wiped off just fine. The only problem would be any marker that gets into the grain of the wood doesn't wipe out easy and can leave some residue. If a grain filler was used first, it wouldn't get in the grain then. Baltic birch has pretty fine grain though, so it may not be a problem.

One drawback though, unless you use a lot of it, it's about $120 for five gallons (in my area) and what you catalyze has to be used up before it starts to gel. Although I've found that it has a pretty good pot life. I've used some that has been catalyzed up to two weeks later as a first coat with no problems.


  • Scott, thanks for the heads up on Gemini. I can't find anyplace that sells it local to me and haven't found an online except from the company. It seems like they may have changed the numbering convention from looking at their website, but I suspect its the long pot life conversion varnish they have listed.

I went to walmart and bought one can of every clear coating they had and tried them out last night on scrap. I also stopped at truevalue and got a can of helmsman spar poly.

Walmart: Krylon clear, colorplace fast dry clear, kilz clear, minwax fast dry poly, rustoleum clear acrylic. None of these worked. I was kind of suprised the kilz didn't work.

The helmsman spar poly did work pretty well.

I had previously tried some other things I had laying around. Deft lacquer in matt and gloss, minwax polycrlic and a couple of other things. Haven't tried MAS epoxy yet.

I have an order in for frog juice and sculpt's permalac. We'll have to wait and see on those, but its nice to have something that works that I can get locally.

Got an online place for gemini?

  • My guess would be that most of the clears you have tried are low on the solids and not as chemical resistant.

I'm not sure if Gemini has some different numbers, but the Ultra-Var one sounds like the same stuff.

They show only one distributor for IN. Accessa Coating Solutions in Indianapolis. 800-539-0126

  • Try Target coatings polycarbonate urethane over their universal sealer. Talk with their tech guru, he's pretty sharp.

http://www.targetcoatings.com/coatings.html

Supposedly better than conversion varnish. I just started using some for exterior millwork in a kids play area.

  • Eric: Congratulations on being probably one of the first users in Florida to start going waterborne. At the last IWF show I was at every developer there and they stated that Florida was low on their priority list for setting up distributors due to the resistance of commercial shops to get away from the "cheap and easy" lacquers and varnishes". I'd really like to here more about your experience with the product as it grows.

Dave

  • Thanks Dave! I'm making the switch because of pure business. I like traditional lacquers but the cost of spraying legally is getting pretty steep. After a final conversation with my local fire inspector concerning a legal spray booth I figured forget it, I don't have that kind of money. A lot of guys try to get away without a booth but around here if you get caught it's fine time and they'll shut you down.

So I asked what he thought of me shooting water based. No problem, spray away, booth or not! After talking around I settled on the Target stuff and had a long talk with their tech guy Jeff. Sprung the cash for a really good Asturo gun. I think this is critical for water borne. It works and applies different for sure. You hang on really thin coats and more coats than solvent based. You also don't get the "build up" that solvent gives but it's still pretty good looking.

These newer water borne coatings have much less plastic look to them than the earlier products. Yes, the solvent based look is what we're used to but so far my customer is happy, the fire dept. is happy so I'm happy!

As a side benefit I talked with a few full time finishers via e-mail in other areas who had made the switch. Most never realized what the solvent was doing to them until they switched. They all said they just flat felt better since going water borne.

The water borne polycarbonate urethane is something I just tried. A little different to shoot than the water borne lacquer but this stuff has some pretty incredible properties. Did some reading up and several companies are launching this stuff. It's precat, tough, uv and chemical resistant, water and solvent resistant after full cure. Supposedly better than many conversion varnishes. Had a customer who shoots a lot of CV want to try it out as well. He's beginning to suspect some health problems may be due to skin exposure of the old stuff. It's worth checking out....


  • About 5 years ago I tried several of the Target products including a prototype of the polycarbonate. How is it for shrinkage? For mar-resistance?


  • I got the frog juice in last night and tried it out on a small sheet of 220grit sanded baltic. I sprayed 2 thin coats on it (I used about 2oz for a 30"x30" blank). It didn't seem to build very much, nor did it reject the dry erase marker. My permalac shipment should be here today. I'm going to try a couple more coats of frog juice on that blank to see if I just had too little on it.

If the permalac doesn't work, I'll try target's stuff next.

  • >>About 5 years ago I tried several of the Target products including a prototype of the polycarbonate. How is it for shrinkage? For mar-resistance?<<

I tested the polycarbonate stuff just a few weeks ago and then sent it out on a millwork job that will be exposed to weather and (GASP!) children. The customer figures if the finish lasts a year an a half with the kids (100's a day) it will be pretty good stuff compared to past experience.

I figure that will be the ultimate test for abrasion and mar resistance. Never had any shrinkage problems with the test piece or their Ultima Spray Lacquer. I've been using the USL for several months now and I'm pretty satisfied with it. It does take a little getting used to working with but once you get the hang it applies pretty easy.

  • Permalac isn't resistant to dry erase either. Of everything I've tried helmsman spar urethane. I order some target universal sealer, gloss and matt polys to try next. I had some luck shooting helmsmen canned poly thinned with about 20% mineral spirits from a harbor freight pressure can (aluminum paint can with air valve).

xylene in dry erase markers is rough on finishes.

  • Just tried a little test for you on some test pieces I had shot in the past. I marked with a dry erase marker, waited 5 minutes and wiped off. The Target Ultima Spray lacquer is not resistant but the polycarbonate urethane wiped clean. Just remember if your testing, this stuff takes several days to achieve full chemical resistance!

I'd talk to Jeff at Target for further info.

  • It seems that this topic is off to a rough start.

Single stage topcoats, which are distilate based, made for wood, such as varnishes, and lacquers are relative soft. The reason they work so well on wood is their ability to flex and move around as the furniture expands and shrinks. Sail boats, coated with varnish, are the prime example. On these vessels, it's thick and relative soft.

What is needed here is a catalized clear coat used for cars. We use Matthews but ANY automotive clear should work very well. It takes a few days or heat lamps for curing.

John, I'd suggest you test a dry marker on a automobile finish.


  • Eric, I ordered satin poly, gloss poly and universal sealer. I tried the satin poly (its indoor only) and it does ok. it might need additional time to cure. The gloss which is indoor/outdoor might work...I haven't tried that yet.

Joe, my wife would kill me.

Ragging on thinned helmsman poly really makes poly easy to get on smooth. It takes more coats, but each coat is a lot less hassle.

-- I did find Markee clear dry erase paint. I'll try that next, but at 100+/gallon, its pricey.

  • Did you get the Emtech9300? That's the polycarbonate stuff. That's the one I had success with. According to the sheet it takes 150 hours to achieve full working properties for chemical resistance.


  • Crud, I think I got the oxford because I wasn't paying attention. Its still pretty nice stuff. It won't go to waste. I'll probably try the Markee stuff next if the target oxford gloss doesn't work well enough.


  • That target poly is great. I brushed it on badly and it still came out great. I was mistaken, the oxford poly is all indoor. The next time I order from them, I'll get some of the emtech. I'm ordering markee dry erase paint tonight. its pricey though...$97/gallon, but it should work.

joe...I don't know much about auto finishes. Can I shoot that kind of stuff out of a critter gun?


John, For auto finishes use a hvlp gun to shoot it, but be sure of ventilation. You don't want this stuff in your lungs or on everything in your shop.


  • If you are still looking around for an answer I will throw a few more out to you. For WB try the MLCampbell AquaLente. It is really taking alot of shops in my area from solvent to h2o.

If you are looking for something more along the lines of the auto clears, then I would recommend MLCampbell Euro-X. I used to use Sikkens Auto clears on exterior wood doors, but now use this stuff and it is proving to be an excellent product. But it is a pretty rough produc in terms of health. You need to take the proper precautions with it.

  • I tried the markee clear dry erase paint. It goes on a little rough and doesn't go over wood very nicely. It looks like it would work well on drywall or paint, but so far, not so good. Maybe I can get it thinned enough to work.

Next...the target poly that eric recommended... If that doesn't work, gotta try the aqualente and conversion varnish.

  • So far, the target polycarbonate polyu isn't working too well. It rejects some colors, other colors stain. I'm going to put another coat on it to make it smoother and let it cure some more, maybe its just needs to crosslink more. its been on 72 hours. Gloss works better than satin though.
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