wet sanding

[r1dermon]

man, i've had some cool models over the years, and i've painted them all to a nice finish, however, i just bought a LOC aura, and i want this beast to look SPECTACULAR, so, if you have suggestions on wet sanding primer, please give me some feedback, i've never attempted it, except on a model car, and it came out all bubbly and bumpy. thanks.

 

[Missileman]

My only tip is you need a primer that is wet sandable.
Krylon makes a brown primer that wet sands beautifully.
Don't try wet sanding the Krylon white or grey primers.

 

[r1dermon]

well yeah...but, what im asking is like, what type of sand paper, or emery cloth...how much water...etc...how many coats....im just looking for instruction. i sortof have an idea, but i want to be sure that im not going to screw up my rocket.

 

[sandman]

You have to get the WET/DRY sandpaper specially made for wet sanding.

It'll say so on the back and it's normally Black.

Keep it wet! And wipe off the residue occasionally to check your progress.

I like to "dip" my sandpaper into a cup of water, some people like to pour it on...whatever...develop your own technique.

Carfull...it cuts faster than normal sandpaper! Suprisingly faster!

For smoothing a primed surfase sand first with 220 then 320 before paint...someone else may use a different grit.

I like 400 grit to wet sand between coats of finish color or even 600 grit.

DO NOT use emery cloth!!! That's for sanding metal.

 

[Stones]

I use Painter's Touch by Rustoleum. Wetsands just fine. Here's another must that I'm surprised Sandman didn't mention. The primer/paint has got to be DRY. All the way dry. Like, let it dry for 3-4 days dry. Maybe even a week, just to be sure.

 

[sandman]

The primer/paint has got to be DRY. All the way dry. Like, let it dry for 3-4 days dry. Maybe even a week, just to be sure.

I use Bondo brand automotive primer in the rattle can. I can usually sand within an hour and it works just fin.

Finish paint...OK that's another story...ya gotta wait there.

 

[teflonrocketry1]

I use Varsity brand white sandable primer I purchase from Pep Boys. I dry sand it to 400 grit 15 minutes after spraying it on the model. I typically touch up the primer, or top coat it with Krylon less than a half hour after spraying the primer on. I have ruined too many paper body tubes by breaking through the primer coat when I wet sand. You have to be very careful that the primer is on thick enough to give coverage during and after wet sanding or the exposed part of the tube will expand and cause a blemish that just begs for more primer and sanding. I have not had much success with dry sanding primers except for the fast drying automotive types. Krylon and Rustoleum sandable primers seem to clog the sanding medium in either wet or dry mode.


Bruce S. Levison, NAR #69055

 

[Micromeister]

Most automotive primers are wet sandable, there are different colors for a reason. brown black and grey have the largest particle soilds (fastest build up), red oxide (medium/fine) and white which has the finest (very fine) solids which is usually marked as (finishing or touch-up primer. I ususally don't bother filler the bodytube seams anymore, preferring to use the heavy build-up primers to take care of then in about 3 -4 coats. Quick sand almost back to the tube with 180-220girt dry sandpaper. than a coat of red or a last coat of grey preimer wet sand with 360 grit, than one or two coats of white primer. finish sanding with 400-600grit wet papers. Keep a bag or bucket of dry terry shop rags handy, wipe the model frequently to remove the slop. Keep the sandpaper wet, dipping often into a pail or pot of water often, be sure to change to water before switching to Red Oxide and especially for the White primers. You can usually do this entire process in an afternoon depending on how large the model is For micro's I usually set up a bunch at a time, to keep the job rolling. half drying with I'm sanding the other half. and so on.

 

[Daedalus]

Originally posted by Micromeister
Most automotive primers are wet sandable, there are different colors for a reason. brown black and grey have the largest particle soilds (fastest build up), red oxide (medium/fine) and white which has the finest (very fine) solids <snip>

Thanks for the info, I hadn't realised there was a difference in the particle size. I had always assumed it was just so that layer on layer you could see where the current layer had sanded through. I will have to get some of the larger particle primers to try.

 

[sandman]

I had always assumed it was just so that layer on layer you could see where the current layer had sanded

Oh...that's true too!

For a fantastic finish start with the gray I think that usually has the highest number of solids then after sanding use the black...next down on the solids followed by white...least amount...

It'll show you the high and low points...

But hey!...we ain't buildin' a showcar here!

Yer gonna get it all finished and be afraid to fly it.

Actually you'll probably scratch it all up in the car on the way to the field...I always do!

 

[North Star]

Originally posted by sandman

Yer gonna get it all finished and be afraid to fly it.

Old Rocketry Equation;

The probability of disaster is directly proportional to the ammount of effort expended

 

[r1dermon]

lol, thats the truth....once im done with this puppy, the paint will weigh more than the motor. lol. i've made rockets look good without primer, but every once in a while, you get the occasional crease, and always the molds on the nose cone, and i want something a little bit sleeker for my LOC model. plus, im going with glitter gold and a TON of clear coat, so spotting this bird shouldnt be tough. thanks for all the tips!!