If you want to extend the useful life of a patch of cross-linked smooth prime, put it in the refrigerator when you're done. I've been able to maintain workable smooth prime for many, many hours after I've cross-linked it.
I've got to be honest, I'm not all that nuts about smooth prime. You wind up waiting a long time to get a few coats of this stuff on and it's difficult to see the imperfections that really need the attention. Martin-Senour, PPG, and a variety of other manufacturers offer dry sandable primer-surfacer that flashes in about 10 minutes. You can lay as many coats as you'd like in about an hour with a HVLP gun. The products I've been looking at are used on Corvettes, so it can't be all bad (UV protection and all that). Beside which, it's one hell of a lot cheaper. I'm going to talk to my local PPG guy before I make the switch. If it's a suitable match, I'll never use overpriced, overblown smooth prime again. Mike Meyer ----- Original Message ----- From: "larry flesner" <[email protected]> To: "KR builders and pilots" <[email protected]> Sent: Thursday, June 05, 2003 9:45 AM Subject: KR>Smooth Prime (long) > > > I've just opened my third gallon of Smooth Prime and I'm getting > close to finished on priming my KR. I'll share a few observations > on what I've experienced so far. > > - Read the ( manufactures) directions carefully so you know > what you're doing. > > - A propeller shaped paint mixer on a 1/4 drill motor does a > good job of mixing and it is not necessary to locate a paint > shaker as suggested in the directions. If the primer has set > for some time you will want to use a stir stick to loosen the > solids that have compacted on the bottom of the can when > you mix the primer. > > - The first three coats require adding "cross-linker". I used > a quart fruit jar for mixing. It has to be used in eight hours > so don't mix more than you intend to roll on in that amount > of time. > > - Some light sanding after two or three coats will help get a > smooth finish a bit more quickly and with less effort. The > first coats will have a very rough finish because of the high > solids content of the primer. 240 or 320 grit paper works > well for that. > > - No matter how careful you are you will have "pimples" and > flecks of solids in the finish. These come from primer that > has dried in your paint dish and around the rim of the can and > then find there way into the primer. They will easily sand off > but a better method is to use a small scraper with the single > edge razor blade. Carefully run the scraper across the surface > at a shallow angle and they cut right off. If you sand them off > you will sand off primer around the spot that you will have to > replace. > > - Another flaw you will get is "ridges" in the primer that come from > the end of the roller that you fail to see and don't get rolled out. > Use your razor scraper to remove these also but draw the blade > down the length of the ridge in a near vertical motion. It will only > take off the ridge and not the surrounding primer. > > - The directions say you can either spray or roll on the last three > coats. When spraying it says to add some water to thin the > primer. This also works when rolling and will help to give a > smoother finish. I used a pint jar and added a bit of water at a > time until I got the mix I wanted. > > - I found I could use the primer with a 6" rubber squeegee and > very light pressure to fill minor defects. It dries very quickly and > is ready to sand in a very short time. I added some "micro" to > the primer and used the squeegee to fill slightly larger defects > with good results. > > - When I started I used a plastic spout to pour primer from the > can into my mixing jars. The problem is you can never get all > the primer off the spout and the bottom edge of the can rim. > This will cause you to later get a lot of dried flecks of primer > that find their way onto the finish. When I started my last > gallon I switched to using small disposable cups to dip the primer > from the can. I use my roller to clean out the "dipping" cup and > then toss the cup into the trash, starting with a clean cup on the > next draw. > > - For safety reasons you should wear a mask while sanding. I hate > the mask because my glasses don't fit well and keep "fogging" > as I breath. My solution is to sand in an open area and use two > window fans mounted in a stand. I Keep the fans close to my > work and always keep my head in the direct blast of air and > "up wind" of the area I'm sanding. USE YOUR OWN JUDGEMENT > HERE. > > - Last but not least, the discouraging news. When you think you > are nearly finished, look again. You will most likely find you are > only about half done! > > As always, do your own testing. YOUR RESULTS MAY VARY. > > I hope to be painting in the next 30 days and my painter has > convinced me to use a DuPont paint that sells for $38 a gallon. > I've seen his "work truck" that he painted 8 years ago in his > driveway in Florida and the paint seems to have held up well. > The color selection is limited but the color white available seems > to be what I'm looking for. I intend to use vynal for my trim strips. > More info on that later. > > Happy building....... > > Larry Flesner > > > > _______________________________________________ > see KRnet list details at http://www.krnet.org/instructions.html
