It answered my next question as well. To start the project, sand the wood surface with a 320 or 400 grit sandpaper to remove minor surface defects from the wood. Ignoring that it's not needed for adhesion what it does is pointlessly remove varnish you just applied, only to be replaced by more varnish in the next layer(s)! I had a similar issue recently with the same product, except I was just following the instructions and started sanding. Could you guys recommend a book or lecture notes that is easy to understand about time series? Fortunately, I started on a part that was easy to quickly repair. Forum topic by Thomas Anderson: posted 06-05-2017 03:15 PM: 19133 views: 0 times favorited: 14 replies: Thomas Anderson . Remove all dust. Can you have a Clarketech artifact that you can replicate but cannot comprehend? Apply the second coat of urethane. Apply two to three additional coats of full-strength polyurethane, sanding between each coat. Polyurethane applied to a wood surface when temperatures are below 50 F may take the product longer to dry. There is no substitute for sanding between each coat if you want the best finish. This is one of the other reasons I personally object to that part of the finishing instructions. It does not invalidate any of the other content in the post so we should be good. Clean the sanded wood surface with a tack cloth before applying the first coat of polyurethane. Then dampen a clean cotton cloth in water and rub automotive rubbing compound onto the surface in a circular motion -- the compound will remove any slight scratches left by the sandpaper. Try to get the "non-filling" type, like the waterproof or aluminium oxide. This is very far from the truth, and it wouldn't be an exaggeration to say it can waste 95% of the product that goes on the wood. What happens if you forget to sand between polyurethane coats? So I am playing with finishes for the first time and experimenting with polyurethane. 06-05-2017 03:15 PM . Using public key cryptography with multiple recipients, PostgreSQL - CAST vs :: operator on LATERAL table function. What is the cost of health care in the US? I prefer the 320 grit between coats. That’s why it’s important that you stay extra careful while doing this for polyurethane stains. @bowlturner In error I thought that poly was oil like danish or tung. Aside from the lack of sanding between coats I adhered to the instructions rather well. Allow the first polyurethane coat to dry. 20 posts in 1281 days. Wiping down with warm soapy water would have probably been the first thing I would have tried :-). How to sustain this sedentary hunter-gatherer society? In-between Coats When applying polyurethane, brush along the grain, stretching the polyurethane into as thin a coat as possible. Sanding with 220 grit with only a few passes it looks like I sanded through the two coats down to wood!? Bear with me. In addition to that, sanding between coats specifically should not be relied upon to ensure a smooth, uniform finish (there are much better methods, none of which waste finish needlessly, more on this below). Although some sanding between coats is needed for some users, it's actually a very self-serving direction on the part of the manufacturers as they're assuring you use more of the product than needed. How do rationalists justify the scientific method. Bayne began her writing career in 1975 and studied history at the University of Tennessee. Was the theory of special relativity sparked by a dream about cows being electrocuted? G.K. Bayne is a freelance writer for various websites, specializing in back-to-basics instructional articles on computers and electrical equipment. No one I know of has ever suggested 21 coats of poly. Generic word for firearms with long barrels. There are uncountable examples of this to prove the point, as Bob Flexner makes some reference to in The 7 Myths of Polyurethane on Popular Woodworking. Fold the sandpaper over several times so it fits in your hand. And actually it's not needed between coats of any varnish and never has been . [Useful trick while I'm here: After the varnish has really cured, a brown paper bag is just abrasive enough to knock loose dust specks caught in the surface and polish it a bit.]. Thanks for the article. Nonetheless, water-based stains will always require you to sand between the coats of stain. After the first coat, all you are trying to do is remove the bumps and scuff the surface for the next coat, so 220 is just too rough. Are my poly coats to thin? When they say "sand lightly," they mean very lightly, just enough to roughen the surface a bit to help the layers mechanically lock into each other and reduce the risk of one peeling awsy from the other (which is supposedly possible). Is the word ноябрь or its forms ever abbreviated in Russian language?