Posted by Matt on February 23, 2002 at 21:53:58:
In Reply to: Attn: Matt the MDF guy posted by Bren R. on February 22, 2002 at 13:04:52:
First, Off some great posts by others!! Our shop has dealt with the dreaded MDF paint problem awhile now, we built mdf doors and the customers tried to paint them themselves with bad luck, most painters now know how to deal with it, I will tell you a way where you WILL have good luck anyway, I am sure there are others, but like everyone said, the key is sanding the primer!
Since MDF soaks up any finish quickly the key is to use a primer that drys fast and sets on the surface, I heard some say Kilz, never used it but the stuff is great and will dry fairly quick, Since we rarely finish MDF (painters job) I went to Sherwin Williams and asked the experts (I was painting mdf trim) they recommended a Alklyd base primer which dried quick, then to sand between coats, I used steel wool with the best results, since the paper tended to cut the corners a little, maybe worn out paper but new sandpaper unless used on a flat surface just really sanded to fast in areas, I do use 2 coats of the primer, sprayed on, if brushed I tended to get to thick and resulting in much more sanding DO NOT WET SAND!! Basically if you don't get a smoothly sanded primer your finished piece will not be smooth, just like a car paint job, so sand it so its very smooth with steel wool, next I thinned the Sherwin Williams oil base enamel paint (in desired color and sheen) to its recommended thinning and applied it with a spray gun, this stuff drys SLOW, but after about 12 hrs I steel wooled it again and then applied the final coat the same way, If the dust is kept out, it will come out like glass and very durable, all the pieces I have done this way, everyone believes are made of metal, they come out that nice. Thats what a pro-painter recommended and what Sherwin Williams recommended and it works great, and not that expensive either (just awhile waiting on the oil base enamel to dry) Best of Luck matt