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Sanding Sealer?

Hoomi

Master member
#1
It's been a long time since I built much out of balsa, but I made a camera mount for my Freewing 64mm A-10 out of balsa, and was looking at putting a paint finish on it. The last time I did much in wood, I used sanding sealer on the balsa before the finish. I looked at a couple of craft stores tonight, both of which sold balsa stock, and neither had sanding sealer. Even looking on Amazon, there was only a couple of results. Has the use of sanding sealer fallen out of practice, replaced by something better? Or is it just that working in balsa is increasingly rare, such that few places stock more than just the rudimentary supplies?
 

Turbojoe

Elite member
#2
Dope is getting harder and harder to find in the smaller hobbyist sizes. Not sure it's still available but we used to use Sig clear dope and add baby powder to it to thicken it up. It sanded well and smelled great! I haven't tried it but I've heard of people doing the same with water based polyurethane like Minwax polycrylic. (WBPU)

Joe
 

Piotrsko

Master member
#5
You can still buy a quart of either butyrate or nitrate from univair, but it is $$$. Sealer just raises the sanding fuzz so you can smooth it back down with more coats and it also fills in the grain with talc. Minwax makes 1/2 pints of one step sealer/finish IF you're not using fuel
 

rockyboy

Skill Collector
Mentor
#6
I found that with water based sealers (like the Minwax water based polyurethane) it's important to do both sides at once or it'll warp the wood. Oil based polyurethane spray, spray on varnish, chalk artists spray"fixative", or the classic Sig Sanding Sealer in a can have all worked great for me.
 

Hoomi

Master member
#7
I think we still have some polyurethane at home. I may just go with that.

As I said, it's been a long time since I did much with balsa! The fact that it's lightweight and easy to work with, though, made it ideal for fashioning the camera mount.
 
#8
A good sander can be helpful and the right paper. I have really grown to love sanding various things in my house and now I think I am a pro, even though I am really not. My wife likes to mess with me, she gives me things that need to be sanded (which is not the case) and then she laughs at me when I ruin something. I know what she's doing, but I let her have some fun. I have found a good sander reviewed here online. It was easy to choose Makita sander because it is really the best one. Now I do it much better with the right sander, but there is still room for improvement.
 
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#9
For something to seal the grain and prevent future coats of other things from soaking in and raising the grain, I use shellac. It dries very rapidly and the odor is nowhere near as obnoxious as the hobby sanding sealer that can still be purchased in tiny little bottles, which is nitrate dope with more solids, I believe. Nitrate dope is still available. Check brodak.com for small 8-16 oz tins, or aircraftspruce.com for gallons of the stuff. You can add talcum powder to it for more “fill.”
 

Bricks

Master member
#10
For something to seal the grain and prevent future coats of other things from soaking in and raising the grain, I use shellac. It dries very rapidly and the odor is nowhere near as obnoxious as the hobby sanding sealer that can still be purchased in tiny little bottles, which is nitrate dope with more solids, I believe. Nitrate dope is still available. Check brodak.com for small 8-16 oz tins, or aircraftspruce.com for gallons of the stuff. You can add talcum powder to it for more “fill.”

This ^^^^ and regular hair spray works well to.