What can you thin polyurethane paint with?

Answer 1

Polyurethane is made for painting wood pre-finished surfaces. Depending on the condition of the surface of the wood you can easily judge the prep work that is needed. If there are obvious spots that need filling like nails or screws that are countersinked create a gap between the nail in the hole you will need to first get wood putty to fill in those holes. You can also (and i highly recommend doing this!) get sawdust from the existing wood type and mix it in with the wood putty. This creates a almost untraceable and make the wood look like you didn't put any nails into it. It takes about 1-2 hours for wood putty to dry if you get the wood putty in a small tin that you add water to it dry's much faster. ( i would saw about 1 part water 2 parts saw dust 2 parts putty compound) After all the defects of the wood are done you can start sanding your wood, (I usually use 220 sand paper for most woods) its very easy depending on the condition of your wood. You also want to remove all types of oil and other types of grim like that off wood to because it will make the poly not bond right and will make the project look like crap :X. After sanding get a wet cloth, or a tack-rag and wipe down all of the sawdust free from the substrate. (surface to be finished) After that you will need a small wood trim brush or a normal 4 inch brush depending on the size of the project. Finding the right poly is also a must, there are many different types of poly and some require more skill than others to prefect. I usually use indoor/outdoor compatible wood poly bought at Sherwin Williams. Once you find the right poly you are going to want to put a thin layer of poly on a practice piece of wood if you have never applied polyurethane before it is a delicate process that is master carefully. When you apply your first coat its the coat that seals the poly to the wood. You must be careful not to put poly on to think around edges and corner for it will drip and that is the worst thing that can happen... its very hard to fix depending on the degree of drips, its not like paint drips in much more delicate work than that. I dip the brush usually about 1/5 the length of the brush and start in the middle of the surface of the wood and spread out a even light coat of poly for the first coat. Now poly takes about 4-6 hours to dry depending on what type it is, and i wouldn't recommend touching it until at least 3 hours its better actually to just wait the full time. Then sand because it will feel dry on the surface but it could still be wet underneath the wood where it's trying to bond with the wood surface. After than you must very lightly sand the poly surface you don't have to put any pressure really on it either you can just pass you hand before you add the second coat. You will notice its rough and very coarse. Once sanded it will feel smooth and you must get a damp rag or tack-rag again and take of all of the dust. I usually put three coats on the surface before i call it done.

Answer 2

you can cover polyurethane with either oil or latex paint as long as its prepared correctly. you need to sand it down or scuff it up. then use a good primer.