Terry Bolin

My Feedback: (7)

I use Mico-ballons and ground fiberglass now but I used to hear of builders adding Baking powder to their epoxy to make it sandable... Has anyone done this and how is the results?
Thanks, Terry B

Gray Beard

My Feedback: (-1)

Baking powder I have never tried but talc and baby powder yes. I works very well but if I have micro baloons on hand I use them instead, they are bigger and seem to sand easier. I use the micro baloons for making fillets. When I glass a plane I do use the talc and baby powder though. It fills the weave better and sands very well. I don't use epoxy for glassing though, I use Deft Sanding Lacquer so sanding is easier no mater what I use.

RCKen

My Feedback: (9)

I've never used baking soda as a filler. But I have used corn starch as a filler and it works very well. Not as good as micro balloons but the corn starch is a pretty good substitute if you are out of the balloons.

Ken

box car

Always looking for something new. I mixed spacking with gorilla wood glue, works real good. I got some vinyl spackling and used it to do some filling, this stuff is great.
Ken

Terry Bolin

My Feedback: (7)

So guys, Do the corn starch and or Talc sand easy enough to make a fillet? Like where a wig and fus come together ?
Thanks, T

DavidAgar

My Feedback: (108)

I am thinking that Micro Balloons is going to be the easiest to sand. You want to make it into a thick paste and let it cure real well before sanding. Good Luck, Dave

RCKen

My Feedback: (9)

Dave is correct. Micro balloons will make for the easiest sanding. You can still sand the epoxy and cornstarch mix, but it takes a little bit more work. Not much, but a little bit more. If you can you would be better off using the micro balloons

Ken

Gray Beard

My Feedback: (-1)

Agreed with Ken 100% but using talc doesn't make it all that much harder. I wet my fingers with alcohol when I'm doing the fillet shape so there isn't a lot of sanding when I'm done so no big deal.

Chip_Mull

My Feedback: (1)

How about:

Super-Lightweight Epoxy Filler
Only 3.68 pounds per gallon Bondo is about 10!
Epoxy Tough
Will Not Shrink or Crack!
SUPER-EASY Sanding
Great for Composites, Aluminum, Wood, and much more
Under $20 for a Quart Kit!

http://stits.com/pfdocuments/epoxy.html

WhiteRook

My Feedback: (38)

yes , you can add BAKING SODA to epoxy , to fill , but i havent tried sanding it yet. ive used it as a filler and it works GREAT.

edmoor

My Feedback: (1)

NO EPOXY SANDS WITH BALSA.....balloons or not!!!

Boomerang1

First question would be what do you want to fill?

The first rule of filler is it should be softer than what you are filling.

Balsa, being very soft, needs a VERY soft filler. I have used a ready mixed, super easy to sand drywall filler or the final top coat for drywall patching.

For fibregass parts epoxy & micro ballons works fine as does some 2 part builders fillers. - John.

Terry Bolin

My Feedback: (7)

Thanks for the info guys. I havee been using Micro Ballons and love it. When it comes to sanding the area, I put Masking tape over the balsa right next to the epoxy filler.. Mostly I use it when Making wing and Stab Fillets..I use balsa filler for dings on planking..Much softer.