Filler after fiberglassing

Filler after fiberglassing

Post by Brian Elfe » Mon, 31 Jul 2000 04:00:00



What type of filler should I use after putting on fiberglass?

I've seen Hobby Poxy filler/primer recommended, but darned if I can find
it locally or on the Internet.  I found some Hobby Poxy fast filler at a
hobby shop, but it appears to be for filling wood, not a primer/filler.

I'd like something that can be painted on and sanded when dry.  I don't
think the elmer's stuff fills the bill here.

Brian

 
 
 

Filler after fiberglassing

Post by John Hatta » Mon, 31 Jul 2000 04:00:00


Quote:

>What type of filler should I use after putting on fiberglass?

>I've seen Hobby Poxy filler/primer recommended, but darned if I can find
>it locally or on the Internet.  I found some Hobby Poxy fast filler at a
>hobby shop, but it appears to be for filling wood, not a primer/filler.

Use the same epoxy you used for the fiberglassing, mixed with
microballoons. Start with 3 parts microballoons to 1 part slow-cure
epoxy.

I like to mix in microballoons until it flows, but *very* slowly. put
your rocket horizontally so two fin-joints face straight up, then apply
the mixture, smoothing with a (gloved) finger. If you use slow-cure, the
fillets will smooth themselves out a bit more. They won't require much
sanding, but they should sand beautifully. In general, the more balloons
in the mix, the smoother it'll sand.

Quote:
>I'd like something that can be painted on and sanded when dry.  I don't
>think the elmer's stuff fills the bill here.

Elmers is great for bare wood or phenolic, but I don't think I'd use it
on fiberglass.

---
John Hattan   Grand High UberPope - First Church of Shatnerology


 
 
 

Filler after fiberglassing

Post by Dave Trian » Mon, 31 Jul 2000 04:00:00


Quote:

> What type of filler should I use after putting on fiberglass?

> I've seen Hobby Poxy filler/primer recommended, but darned if I can find
> it locally or on the Internet.  I found some Hobby Poxy fast filler at a
> hobby shop, but it appears to be for filling wood, not a primer/filler.

> I'd like something that can be painted on and sanded when dry.  I don't
> think the elmer's stuff fills the bill here.

> Brian

Hi Brian -

Check out the technical pages at our website. They could help to shed some
light on your question.

http://www.shadowaero.com/Technical.htm

Best regards - Dave Triano, Shadow Composites, Inc.

 
 
 

Filler after fiberglassing

Post by IBPYRONS » Mon, 31 Jul 2000 04:00:00


snip of Brains post to save bandwidth.
Brain what are you wanting to fill?Glassed airframe,fins a nosecone?
 First thing to do is scrub the part with a strong detergent like Tide with a
stiff brisel brush,like a deck cleaning brush.Use 120 grit wet/dry paper and
wet sand the part to remove the high points from the glass.High points is the
rough surface left from the glassing(if you look closely at the surface after
glassing the pores seem to be raised up a bit)This is what you want to sand
away,leaving a smooth surface but with zillions of unfilled little squares.Sand
again with 320 to smooth out the scratch marks.Scrub the part again to remove
any leftover grit from the sanding.Spray on an even, medium heavy coat of a wet
sandable primer when the part is dry from the last wash job.Wet sand until  the
the primer is pretty much gone,you should be left with a part that looks like
it has lots of little primer squares with white lines in between all the
squares.Rinse off the part and let dry.Shoot on another coat of primer and wet
sand untill smooth with finer and finer grades of wet/dry paper untill you are
happy with the surface.
I use this method on glass airframe and it works great.I have a small childs
wading pool set up on 3 sawhorses in the backyard with about 8 inchs of water
in it.I put the airframe in the pool and sand away with no leaky hoses to mess
with,and the wet/dry paper never loads up either.
 as a free tip,don't use the tub in the bathroom to wet sand in.It will work
but the ring left from the sanded off primer is a real pain to get out.I'm
still in trouble years later with the wife for this one.Don't ask about speed
curing parts in the oven.
Tom
 
 
 

Filler after fiberglassing

Post by Thosz » Tue, 01 Aug 2000 04:00:00


This guy's definately got it goin on! Tom, I like how you think! When im cut,
do I not bleed red oxide sandable?
 
 
 

Filler after fiberglassing

Post by IBPYRONS » Tue, 01 Aug 2000 04:00:00


Quote:
>This guy's definately got it goin on! Tom, I like how you think! When im cut,
>do I not bleed red oxide sandable?

Well it sure looks the same,don't think it will sand as good though.
As for the last part of my post I think we should all get together and get a
new law passed as to a time limit wives can remember stuff like primer ring
around the bathtub or using the oven to speed cure parts.How many of us have
swiped the poultry baster from the kitchen for that gotta do it now project at
2 AM?
 What about the oddball Tupperware lids that no longer have the container(that
would be the mixing cups for some project in the past)that you used to mix a
small batch of 5 minute epoxy and get yelled at when they find them while doing
laundry.
  Better yet why don't they see the need to use the fancy butter knife from
aunt Bessie to spread epoxy/microspheres around the ends of the fin fillets so
you can blend them in and make the fillets look killer.
 But nooooooooo,the wife has the girls trained to rat me off when I head for
the kitchen."Mom,mom, dads in the kitchen going through the catchall drawer
again"
  And yes you can ruin CorningWare while mixing propellant.
 Tom(hey it only took me a half can of Comet cleanser to get rid of the tub
ring)Cloud
 
 
 

Filler after fiberglassing

Post by Thosz » Tue, 01 Aug 2000 04:00:00


Tom,
I can't begin to count how many times Ive snatched the dogs water dish to use
for wetsanding,or slipping into the kitchen for a few "tools' carefully  hidden
in my waistband. it got so bad that I was being frisked before I got to the
garage.Whats a few pieces of bondo covered flatware,more or less?And for future
reference,those 5 quart plastic icecream tubs have the best damn epoxy stirring
 lids ever.I guess I really should have waited till the ice cream was used
up,but whats a little freezer burn?it was only vanilla anyway.
 
 
 

Filler after fiberglassing

Post by Bruce Kirchn » Tue, 01 Aug 2000 04:00:00


Quote:

>What type of filler should I use after putting on fiberglass?<

Depending how deep, Bondo for large deep areas. Spot putty for small scratches.
(Kombi Putty).
--

Bruce Kirchner
TRA L2 #5888       NAR #69850
Michigan Team 1   HUVARS
Visit My Rocketry Home Page - http://members.aol.com/balthezar/index.html
Proud Gun Owner!

 
 
 

Filler after fiberglassing

Post by Brian Elfe » Tue, 01 Aug 2000 04:00:00


Quote:


>>What type of filler should I use after putting on fiberglass?<
>Depending how deep, Bondo for large deep areas. Spot putty for small scratches.
>(Kombi Putty).

Everything I've seen says never to use Bondo, as it is polyester instead
of epoxy based.

Brian

 
 
 

Filler after fiberglassing

Post by Bruce Kirchn » Tue, 01 Aug 2000 04:00:00


Quote:

>Everything I've seen says never to use Bondo, as it is polyester instead of

epoxy based<

Are you doing epoxy based fiberglassing?  I'm sorry, I assumed you meant
polyester resin and MEK Peroxide. No, I wouldn't use Bondo over an epoxy based
finish.
--

Bruce Kirchner
TRA L2 #5888       NAR #69850
Michigan Team 1   HUVARS
Visit My Rocketry Home Page - http://members.aol.com/balthezar/index.html
Proud Gun Owner!

 
 
 

Filler after fiberglassing

Post by Bill Baldwi » Tue, 01 Aug 2000 04:00:00


Quote:

> As for the last part of my post I think we should all get together and get a
> new law passed as to a time limit wives can remember stuff like primer ring
> around the bathtub or using the oven to speed cure parts.

All in favor.................AYE

(amazing the memory, can even tell ya the day of week, 9 years ago)

Quote:
>  What about the oddball Tupperware lids
>   Better yet why don't they see the need to use the fancy butter knife

"Mom,mom, dads in the kitchen going through the catchall drawer

Quote:
> again"

>  Tom(hey it only took me a half can of Comet cleanser to get rid of the tub
> ring)Cloud

Tom   how long ya lived in my house without me knowing?????
 
 
 

Filler after fiberglassing

Post by IBPYRONS » Wed, 02 Aug 2000 04:00:00


Quote:

>Tom   how long ya lived in my house without me knowing?????

It's been awhile Bill,surprised you didn't miss that roll of 6oz roll of cloth
being used up and those 6in diameter airframe tubes laying around the garage.
 Fighting the mutt for the dog chow isn't so bad at dinner time but could you
please leave out a sleeping bag.The garage floor gets cold at night.
Tom
PS:buy more epoxy,I feel a building binge coming on.