In another thread Wood_ogre had mentioned that Zinsser Bulls Eye Seal coat may work as a sealer coat for EPS. I was wondering if anyone here has experience with this product? I have some questions I hope to find answers for.
Does it make the foam brittle?
How far into the foam will it penetrate?
How much is required (volume and # of coats)to effectivley seal a board ?
Any noticible weight gains or losses over the standard methods of spackle or epoxy/micro ballons?
When used with spackle will it provide a surface suitable for detailed foam sprays?
Best method of application?
Is there a minimum/maximum time after appplication to laminate in order to get the best epoxy bond?
I see that it is resistant to yellowing, will it make a good sealer over artwork on sanded hotcoats?
I’ve noted that it provides a barrier for waxes and stearates and prevents fisheyes in laquer finishes, will it solve the fisheye problems with epoxy glosses as well?
De waxed shellac will go a long way to prevent fish eye. But there are other things that must be done in prep too. I do not even know if it is compatible with EPS thats why I brought it up. May be if I get a little time I will experiment with it. Shellac dries fast, so fast that there can be trouble with brush marks with a 2lb cut. 3lb cut is better for brushing. I never brush only spray. There is no time factor between the shellac and a topcoat. I think you would not want to use it as a barrier between coats of epoxy. Epoxy bonds best to epoxy. Your fish eye problem is contamination, if your prep is done correctly you will not have fish eye. Tell me your complete finishing schedule from prep to gloss and possibly I could pick out what is going wrong. I think you are saying the fish eye is in your epoxy gloss coat. How do you do a gloss epoxy. West systems epoxy recomends you use a varnish over epoxy. What kind of resin are you useing and what do they recomend? Epoxy is softer than polyester, I think epoxy would not hold a gloss for long. Shellac would not be durable enough as a top coat. I think that useing shellac between epoxy hot coat and an epoxy gloss coat would not be a good idea. I think to get a high gloss with any finish you would have to rub it out from wet to polishing compound. There are no shortcuts in finishing. Allthough an off the gun finish would still be a nise finish on a surfboard and wouldn’t be as slippery as a high gloss polished finish. Aloha Wood_Ogre
Thanks for the reply Wood_ogre, alot of my questions are answered. Seems that since shellac is cut with Denatured alchohol, it shouldn’t have issues with EPS, I’m gonna go put some in a container and find out.
Yes the fish eye in the gloss coat with epoxy (resin research)has been an ongoing struggle to perfect. I sand my hotcoat to 100 grit (always non stearated paper), paint using liquitex acrylics for art/pinlines diluted with futres acrylic floor polish to spray. A couple of coats of futures over the paint in order to give me something to scuff up without removing paint. I then let it dry for a day, scuff with a gray autobody abrasive pad (scotchbrite) until artwork is dull,wetsand with 800 grit around the tape lines to bring down the ridges (bare skin never touches the board again after this point). I then wash the board with tap water and sunlight liquid dishwashing detergent. In preparation to gloss I bring the room temp to 75 degrees, measure my resin (1oz per foot of board) and warm it in a bowl of hot tap water. While the resin warms I wipe the board with denatured alchohol (avoiding paintwork)and lint free cloth. I blow down my glossing brush with compressed air to remove loose bristles, dust. I then mix resin adding 2cc Additive F per ounce of hardener, set the resin aside briefly while wipe the board one last time with a micro fiber tack cloth.
Unpainted boards I can achieve a near flawless finish on, but paint and pinlines on sanded hotcoats are troublesome. I use 3m 233+ for masking and I suspect the adhesive may be a contaminate (I’m gonna try some 3m “highland 2727” as per Kokua’s suggestion in another thread). Also a contaminated air source is suspect. If the shellac provides a good surface to airbrush on foam, alot of my troubles could be solved, but it’d be nice to solve the painted hotcoat fisheye problem. Any advice is greatly appreciated
Wow, you really do take some steps to have a clean board for gloss. The only thing I read which made me think twice is the tack cloth and the possible contaminated air source. Is a microfiber tack cloth sticky/waxy like regular cheesecloth tack cloths? (I have never used one) If so, there may be the problem. If it doesn’t have any tackiness to it, though, I don’t know, because I do almost all of the steps you describe, and if I get any separations/fisheyes, it is only one or two, probably where I touched the board without gloves (usually not on the painted areas). I have not had any problems with 3M 233+ tape, except it pulling up paint when airbrushing on foam. I also don’t seal my paint with future, but I don’t think that would make much difference if I did.
As far as the air source, other than some type of filtration setup, I am not really sure. Oil in the air source could definitely be the source of your problems, though, especially since they occur only on the paint. If the fisheyes only occur on the paint, that may exonerate the tape…
I hope you get it sorted out, and if you do, let us know how you did…
I use de waxed shellac at work but didn’t think about it on compsand board skins or EPS.
I have a friend that asked me what he could use to seal wood with
oil painting art on it before adding a 3/8 epoxy coat.Right now he uses
varnish to seal the oil paint. He takes big $800 exotic Burl venners on a composite
and adds a semi-transparent oil painting then builds a dam and then epoxys a thick layer on.
They are mostly female nudes based on the grain and burl shapes.What do you see when you look at wood.
He has built a carbon filtered hot room in his garage for finishing but would like to use some thing less toxic than varnish.Would de waxed shellac work? It would speed up his turnaround times.
Hi MaxMercy. I know the tack cloths you speak of but the ones I use are just a rag with really fine looped threads to catch dust particles. They work really well, reusable after a wash and free of wax/adhesives. The fisheyes I find are worst over areas that were masked with tape for the spray and wiped with alcohol. Seems like I have to go to excessive lengths to get a get a good finish, but I knew epoxy was gonna be a battle considering the cold weather/high humidity here.
Ian , De waxed shellac is compatible with all finishes and is used for sealing wood before finishing especially helpful for oily hard wood with pitch pockets.Not only that the solvent for epoxy is DNA and the solvent for Epoxy is DNA that should tell you something! Not all varnishes are compatible with Epoxy. What brand of varnish is he useing? Aloha Wood_Ogre
Stevil, Air can be used to blow out the dust from the pores of wood before applying the Zinsser Seal Coat. But that air should be filtered out at the compressor. The Seal Coat will seal in all the contaminates. Don’t use air aftere that. Aftere sealing the work is considered clean and you have to keep it that way so it is best if you use vinyl gloves aftere that.Neoprene gloves can contaminate depending on the brand and what finish you use. I want to know how you clean with the Alchohol. Alchohol can be a big contaminat. If the rag is wet all it is doing is pushing the crud around the board and depositing in different places Then the DNA evaporates and leaves the crud there allthough you do get some of it… When your board is washed if the dishwashing detergent is scented it can be considered contaminated, Colored rags are considered contaminate especially if they have been wetted with solvent.Usually a solvent wash is not needed, use automotive car wash liquid, and scotchbrite green pad and rince with a lot of water. Cleaning before doing resin work can be done with a white old bed sheet and distilled water. Soak the rag ring it out completly and wipe turning the rag often. When done with this . Do it again with another rag and then a third time with another rag. You should be ready to finish. If you still have trouble try this. Take a clean white bedsheet rag about 1 foot by 2 foot lay it out on a clean surface (Formica) Take a coulpe teaspoons of epoxy resin and drip it over the cloth, splash on some DNA untill it is very wet and crumple it up and twist it around a bit then roll it up and wring it out as much as possible, if there is enough resin in it it will feel moist but not sticky . If there is to much resin it will be sticky, add more DNA and wring it out again. If it feels dry it need more resin.(this is resin without hardener!) This is a safe tack rag to use for cleaning a resin board. Hope you still have your gloves on. Just before applying your finish resin warm your board with a heat gun , a couple passes is enough. Now you are ready to mix your resin and go to it. About the brush dont blow it with compressed air.The day or so before you are going to use them wash them with Laquer thinner working them hard into the bottom of cup to work out any loose bristles. then wash them with auto wash liquid and rinse very well. let them dry, after they are mostly dry you can finish them with a hot air gun, make sure they stay clean.For spreading epoxy Cut about a half inch off the bristles with sharp scissors. For tiping off a finish coat leave them long. Acetone should not be used on epoxy, save it for the poly. It often isnt possible to have a clean area to finish. you can clean your work area a couple days before but not the day you finish. Most of the crud that gets in your finish comes down, Gravity . Hang a clean sheet of plastic above your work, it helps a lot. there is dust on flat surfaces don’t stur it up, Gravity will hold it there unless you have gusty winds or turn on a fan. If you think you are having tape contamination trouble try the green sensitive material tape. But ussually if it is a tape problem it is because it was wiped with DNA. Hope there is something here that is helpful. Remember ,clean,clean,clean=no fish eye. Oh yes you can allso put your resin and hardner through the cone paint strainers before you mix them. All of this information is things that I do in finishing in my shop .Aloha Wood_Ogre
All great info! Thanks. I can see how my DNA wash is just moving the crap around on the board instead of removing it. I never made a connection that blowing the brush off with compressed air may be contaminating it. I used to lightly blow the boards down with air before glossing then switched to the tack cloth and eliminated alot of fish eye. Filtered resin and hardener is something I’ve been practicing for some time, it eliminates alot of zits. I’ve found that heating and filtering additive F really improves the finish as well.