- Jan 20, 2009
- Reaction score
So I finally decided to try Kilz as a primer and quickly discovered it doesn't work well with wet sanding. Seems to be a bit too poreous even after two thick coats.
I think that may be your problem. Kilz is thick stuff and takes a while to dry thoroughly.Nope, the can says oil-based interior. The high spots seem to have dried and are not as pronounced as they are in the photo. Perhaps I didn't wait long enough to try wet sanding. I'll let it sit in the AZ sun all day and see if that makes a difference tomorrow.
After spraying kilz, I let it sit for at least a week before trying to sand it. Even then, it does tend to load up the sandpaper quickly (but it DOES fill great!).Kilz is thick stuff and takes a while to dry thoroughly.
FWIW, thinned epoxy will also work very well.If I were doing HPR, and filling plywood fin grain, I'd use Kilz again. I'm back to LPR/MPR only, and Kilz is not part of the solution for me any longer.
http://www.bsi-inc.com/Pages/hobby/epoxies.htmlFWIW, thinned epoxy will also work very well.
I filled the grain of a basswood nosecone and transition with laminating epoxy, and the amount of sanding required was minimal.
Any epoxy, thinned with acetone, will work quite nicely, and sand easily. Saves you from buying extra epoxy.
Good stuff. Poly-Fil is a very similar product.
I believe that there are two types of Kilz being sold. The people who use it (I'm not one of them) recommend using the Original Kilz, which is readily available (and in fact, it seems to be the variety that is most commonly stocked, from what I have seen).I have to wonder if Kilz, like Krylon, had to change formulas for EPA reasons. I say this because I used to have great success w/ Kilz from the rattlecan. I could wet sand it, and a single coat filled slight imperfections (after sanding FnF, etc). It was great stuff.
The last few cans I have used spray on too dry, leaving pores and sometimes just flaking off. I nearly ruined my beloved Centuri Sat V because the spray blobbed on, and really made the plastic wraps look crappy. I thought it was me, until reading this thread.
I know there was a new formulation, but it used to say on the label -- something like low odor, or such. Enviro regs are going to be the death of us all!!
I'd never use Kilz on plastic. It was meant as a sealer for porous surfaces, such as sealing stains on drywall, sealing in dark colors when repainting a room in light colors, etc. The plastic on the Saturn V probably needs no primer, or a super light coat of an automotive type primer, at most. Kilz has WAY too many fillers for plastic. And I'm not sure it would really bond with plastic.I nearly ruined my beloved Centuri Sat V because the spray blobbed on, and really made the plastic wraps look crappy.
Krylon primer didn't bond too well with plastic either when I tried it. I never tried Kilz on plastic. If the plastic cone has any molded detail on it I would definitely NOT use Kilz even if it does stick.And I'm not sure it would really bond with plastic.
I wet-sand my sealer/filler coats on nose cones and fins (after first sealing the balsa), but I rarely wet-sand anything on the airframe. I lightly dry-sand the primer layer, which is usually sufficient; if there is any rough spots in the primer layer after that, I add another coat of high-build primer to fill them in. But a couple of coats of primer has always been enough. Getting your rattle-can application technique down, so that you can give the rocket light, even coats really helps. I don't know about Kilz, since I have never used it, but with other primers (like Krylon or Dupli-Color), if you apply them well then you shouldn't need to do very much sanding. If I ever have any really rough spots left after lightly sanding the second coat of primer (it has happened a couple of times), I sand everything down bare and start over, rather than keep adding more primer. I learned awhile ago that thick coats of primer on rocket body tubes will lead to paint chipping very easily. Although I use Dupli-Color High Build Primer, I don't use it to try to cover over any surface defects, including visible spiral grooves. The time to correct those problem areas is before you start applying primer.I would not reccomend "wet sanding" any primer if at all possible.
Always good advice when you are painting, no matter what type or brand of products you use. Work methodically and thoughtfully, one step at a time. Don't try to rush things or combine steps.and most important -don't get in a hurry