In a comment, Scigs asks:" . . . I notice you use grey filler primer after filling your fins, then sand most of the primer off. You then follow this up with a base of gloss white. Just wondering why gloss white vs. flat white or white primer after sanding the grey primer. I'm not questioning what you do, but more for my own practice. Just curious to hear the reason behind gloss white undercoat vs. flat white."
Hi Scigs,
First, a little back tracking -
When I started building model rockets in 1969, I used sanding sealer as recommended in the Estes instructions. FOUR brushed on coats, sanding between coats. Results were pretty good, but it took four applications.
Centuri would say to use four passes of Balsa Fillercoat. I don't have much experience with that product.
I always kept looking for a more efficient filling process.
When I got back into the hobby, the talk was Elmer's Carpenter's Wood Filler, or CWF.
PASS 1: One brushed on thinned coat and sanding to surface. This still left a little balsa grain or tube seam.
PASS 2: Follow up with spray filler/primer. I tried the Rustoleum and some other cheaper primers, but they sanded like rubber! Sanding the Duplicolor Filler/Primer (FP101) was much easier. It's probably dustier, but doesn't load up the sandpaper as quickly. CLICK HERE
I use the Duplicor Filler/Primer more as a second step filler, not as a foundation under the final color.
I follow the two pass fill method shown above with a light first coat Gloss White instead of flat white.
The Gloss White shows off surface imperfections where you wouldn't see them using a flat white. Gloss paint shows every glue blob, uneven fillets, mold seams, tube seams or remaining balsa grain.
Any imperfections (there are always some on every model) are lightly sanded with 400 grit or finer before the second light coat of Gloss White. If the surface looks good after the second light coat, a final (slightly heavier) coat of Gloss White is sprayed.
The gloss white easily covers what's left of the gray primer on the model surface.
For the Newbies - All light final colors look better over a white undercoat.
Many finished models have mostly white areas. I don't see a reason to spray flat white then follow with a gloss white afterwards.
The only time I would use a flat finish (as a final color) is if it were a competition scale model. Flat white finishes get dirty fast! For sport flying, gloss paints clean up easily after a sweaty Florida club launch.
I read about some builders filling process. Some use Bondo, others do four passes of sanding sealer, then three passes of primer and sanding before color coats. With the number of builds I do, I wanted something quicker that gave good final results.
As always, this is what works for me -
I'm sure I'll get a comment saying: "That's not the way I do it!" That's fine, we all have different ways of building rockets. Keep doing what works for you.
Chris,
ReplyDeleteThanks for the detailed response, makes a lot of sense to me and I don't understand why anyone would question anything you do. Now that does not mean I don't have a couple of questions....
1. After applying the Grey primer, how long do you wait to sand? And what grit sandpaper do you use on the grey primer before adding the gloss white?
Hi Scigs,
ReplyDeleteA fairly heavy single coat of Duplicolor Filler/Primer (FP101) dries quickly, dry to the touch in about 10 minutes. I can sand it after about 30 minutes. I usually remove the bulk of the primer with a (fine) 220 (some 200 brands are coarser than others) until I just start to see the body tube peeking through. Then I follow with a fine 400 grit to remove any scratches.
Chris,
ReplyDeleteAre you doing the sanding with your great planes sander or just holding the paper in your hand? Thanks.
Hi Anonymous,
DeleteRounded surfaces (Tubes, nose cones and rounded fin edges) are sanded holding the sandpaper with my fingers. Flat surfaces are sanded with a sanding block.
Chris, You said you spray the rocket with a coat of gloss white, sand and apply a final coat of gloss white. When using lets say Rustuleum, the recoat is within one hour or after 48 hours. So do you just give one spray, let dry and sand and apply second coat after 48 hours? Or does your one coat of white done in multiple light coats within the hour window? I hope my question is not too confusing. Thank you.
ReplyDeleteHi Scigs,
ReplyDeleteThe first white spray is light. I give it a day or so to dry before sanding and smoothing any irregularities with 400 grit. I'll wait another day before doing the heavier coat. So there is actually 48 hours between coats.
You could spray additional coats within the one hour window. If I were to spray more coats (after the initial coat is sanded and smoothed) I usually wait 15 minutes between coats.
The Ace Premium enamel I've been using has been pretty good so far, except for their Gloss White. The Gloss White dried flat! It seems fast drying, but I still paint more coats within an hour.
Chirs, Normally, how many rockets are you building at a time?
ReplyDeleteHi Scigs,
DeleteIt varies. For a while I was building two of the same model, to be written up on this blog. One rocket to keep, one to sell on Ebay. But the collector buyers on Ebay aren't bidding on finished models like they once did.
Recently Estes sent me 12 builds, two each of six different kits. That took about 8 weeks to get them all finished.
Rocketry is a full time job for me now between builds, this blog and bagging up Odd'l Rockets kits and accessories.
Wow, rocketry as a full time job, sounds like fun. I hope to retire in 5 years and cannot wait to spend more time on my hobbies. Right now because of work it can take a couple of weeks to finish one rocket. I have collected a lot of old vintage Estes and Centuri rockets that I have still have to build. It seemed doable at the time since Estes was not coming out with any new kits. Now Estes is coming out with too many cool rockets that I want to build, but my build pile is pretty big. There are times I just thought about building the rocket, paint the rocket as is then apply the decals. Of course I have never had much luck just painting raw balsa.
ReplyDelete