Advice on sanding fibreglass

Hey all,
I'm planning on starting to build a molded kit in the summer and in
the meantime I'm trying to perfect my fibreglassing skills by building
a toolbox (and making all the rookie mistakes on it instead of a wing).
I went to the EAA sportair workshop which was awesome but it primarily
focused on the core shaping, laminating and bonding and not really on
sanding, trimming and finishing. Anyway, I need a tad of advice on
sanding and trimming excess fibreglass. First, what is the best type of
clothing to protect your skin from rashes and irritation from all the
dust? Also what kind of sandpaper should I use? grit? wet? dry? moist
:-)? Any other special considerations I should be aware of?

Thanks,
Omri

Kent Ashton wrote:

I've sanding a few Cozy/Long-EZ airplanes and I never had any problem with
rash or dust from that but sanding those UNI landing-gear struts will make
me itch for a day. Somehow those UNI fibers get pulled off longer and
form little needles.

Just a heavy long-sleeved shirt and a regular dust mask will do OK for me.
--Kent



From what I know of fiberglass work your not supposed to sand into the
fibers. Just till you BARELY expose the surface of the fiber. So If your
pulling enough fiber off to stick into yourself and cause a rash you are
way overdoing it.
Anyone else to comment, maybe I'm wrong but I think I'm close!
John

I've sanding a few Cozy/Long-EZ airplanes and I never had any problem with
rash or dust from that but sanding those UNI landing-gear struts will make
me itch for a day. Somehow those UNI fibers get pulled off longer and form
little needles.

Just a heavy long-sleeved shirt and a regular dust mask will do OK for me.
--Kent

From:
Hey all,
I'm planning on starting to build a molded kit in the summer and in
the meantime I'm trying to perfect my fibreglassing skills by building
a toolbox (and making all the rookie mistakes on it instead of a wing).
I went to the EAA sportair workshop which was awesome but it primarily
focused on the core shaping, laminating and bonding and not really on
sanding, trimming and finishing. Anyway, I need a tad of advice on
sanding and trimming excess fibreglass. First, what is the best type of
clothing to protect your skin from rashes and irritation from all the
dust? Also what kind of sandpaper should I use? grit? wet? dry? moist
:-)? Any other special considerations I should be aware of?

Thanks,
Omri

On Sun, 24 Apr 2005 14:46:23 GMT, UltraJohn
wrote:

Kent Ashton wrote:

I've sanding a few Cozy/Long-EZ airplanes and I never had any problem with
rash or dust from that but sanding those UNI landing-gear struts will make
me itch for a day. Somehow those UNI fibers get pulled off longer and
form little needles.

Just a heavy long-sleeved shirt and a regular dust mask will do OK for me.
--Kent



From what I know of fiberglass work your not supposed to sand into the
fibers. Just till you BARELY expose the surface of the fiber. So If your
pulling enough fiber off to stick into yourself and cause a rash you are
way overdoing it.
Anyone else to comment, maybe I'm wrong but I think I'm close!

Pretty much, but not sanding into fibers is getting ready for the next
lay-up. You will sand into fibers when tapering a lay-up such as when
you add a couple layers at fuselage seams and then sand them to match
into the sides and bottom, or where ever they might be. Another
source of fibers (and they really itch) is sanding down a mill fiber
fill. It's normally used in places where you are going for strength
and I haven't run into many places where I needed to sand it, but man!
mixing up a batch, plus throwing in a little Cabosil to keep the resin
from running out is like playing in a roll of attic insulation.

As Kent said, long sleeve shirts with snug cuffs, gloves, Welder's
skull cap (if you have hair) and a good respirator. NEVER sand
fiberglass or resin without a respirator. Make sure it's a good one
too. I work with Vinyl Ester Resin (Derakane) and that stuff is
potent once it has been catalyzed. Smells nice before that. I use a
good organic vapor filter with a dust filter screwed on over it. I
have the kind that uses matching filters that gasket together and the
dust filter keeps the crap out of the activated charcoal.

I typically take the activated filters and put them in "Ziploc bags"
when not in use. Otherwise the carbon is soaking up *stuff* and
shortening its useful life.

I can work inside the fuselage wiping down parts with Acetone and
never even smell it. Just reposition the mask which breaks the seal
to your face for an instant will prove the filters are doing their
job. :-))

Don't take shortcuts and do "just a little sanding" without the mask.
If you are like me a little sanding may turn into an hour or two.

Good Luck,

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

John

I have had way too many hobbies, including boatbuilding. I have
sanded plenty of fiberglass, mostly without a mask, and now that I'm
older and maybe a little wiser I expect that those several pounds of
dust that have made their way through my lungs to cause some trouble
later on. Dust can get into your eyes, too, even with goggles, and
cause eye irritations that make you look like you've been on a big
drunk. And it didn't seem to matter how much clothing I wore; it got
into everything and made me itch. A cold shower gets most of it off,
while a warm shower can open the pores and let it in so it can bug you
for a few more days.
I have sanded it wet a few times (with air sanders!) and there's
no dust at all, but you have to make really sure things are absolutely
dry before any further layup. Any moisture that gets into the matrix
could cause structural problems. A lot less big a deal in boats than in
airplanes, since most boats are way overbuilt.

Dan

Make sure to wear a dust mask. I was sanding my project without wearing
a mask consistently and got it into my lungs and triggered an asthma
problem for a year. AND dont rub your eyes with your dusty hands - my
face got swollen one time really bad. The epoxy/fiberglass dust is
worse than the epoxy mixing fumes. Otherwise the fiberglass dust is no
problem.

You can easily trim excess cured fiberglass while it is relatively soft
and not 100% cured.
====================================
SQ2000 canard: http://www.abri.com/sq2000/

wrote

I have
sanded plenty of fiberglass,
; it got
into everything and made me itch. A cold shower gets most of it off,
while a warm shower can open the pores and let it in so it can bug you
for a few more days.

Another good clue for all you plastic airplane guys, is to spray your skin
with hairspray before, and after you sand. When you get in the cool shower,
it will wash off much better. It clogs the pores, so it does not go down
into the pores, then the after spray clumps the fibers together, so they
stay together, and wash off without going into your pores. Spray deodorant
works, too.

Try it! It really works!
--
Jim in NC

On Tue, 26 Apr 2005 22:44:27 -0400, "Morgans"
wrote:


wrote

I have
sanded plenty of fiberglass,
; it got
into everything and made me itch. A cold shower gets most of it off,
while a warm shower can open the pores and let it in so it can bug you
for a few more days.

Another good clue for all you plastic airplane guys, is to spray your skin
with hairspray before, and after you sand. When you get in the cool shower,
it will wash off much better. It clogs the pores, so it does not go down
into the pores, then the after spray clumps the fibers together, so they
stay together, and wash off without going into your pores. Spray deodorant
works, too.

Now that sounds really, really dangerous.
I load up on deoderant, a shot of hair spray and holler, "Dear, I'm
going out to the shop for a couple of hours"... "BANG!"

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
Try it! It really works!

On 26 Apr 2005 17:20:14 -0700, "abripl"
wrote:

Make sure to wear a dust mask. I was sanding my project without wearing
a mask consistently and got it into my lungs and triggered an asthma
problem for a year. AND dont rub your eyes with your dusty hands - my
face got swollen one time really bad. The epoxy/fiberglass dust is
worse than the epoxy mixing fumes. Otherwise the fiberglass dust is no
problem.

There are a number of "It depends" here.
Whether One of the epoxies, or ester type resins some people develop
severe allergic reactions to them. If that happens, it's time to sell
the project and move onto something held together with rivets.

Another source of irritation: Some poor souls are allergic to Latex
and we use Latex gloves by the box.

Also the fumes from Vinyl Ester resin just plain aren't good for a
body...unless you want to preserve it.

The problem with fiberglass dust, is It contains mainly Silicon
Dioxide SiO2 (Quartz) plus fine particles of resin and many a sand
blaster has ended up with severe lung problems. Now, if you do sand
blasting in industry I believe it's lung X-rays at least once, if not
twice a year. The super fine quartz gets into the small pockets in
the lungs and does not come out, much like the black lung disease
suffered by coal miners.


You can easily trim excess cured fiberglass while it is relatively soft
and not 100% cured.

My manuals recommend trimming in the "Green State". When the cure is
just right it's like cutting soft plastic.

Of course there are both areas and times when cutting in the green
state just isn't practical.

Well... Back to the shop to coat the elevator ribs with a micro sphere
and resin mix to seal the foam.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

====================================
SQ2000 canard: http://www.abri.com/sq2000/

"Roger" wrote

Now that sounds really, really dangerous.
I load up on deoderant, a shot of hair spray and holler, "Dear, I'm
going out to the shop for a couple of hours"... "BANG!"

So you use open flame for sanding, or is there something else you want to
tell us?
--
Jim in NC