another gelcoat story

JJ Sinclair wrote:
Brad, I wouldn't brush on the primer, half your sanding will be to
just remove the brush marks. You can get a cheap gun and compressor
for this. It is usually best to use the primer that is recommended by
the paint you are using, but most are gray in color and this will
start to show through if (when) you get a little to heavy handed with
the wet sanding during the finishing process. That is why I use PCL
Polyprimer, because it is pure white and believe me white is the way
to go. You do need good ventilation any time your spraying anything,
not only to prevent trapping unwanted by-products in the paint, but
you don't want to be trapping any of this stuff in your lungs, either!
That is REALLY true when using uretahne, we had a mechanic here who
recovered a Cub in the dead of winter with propane heaters running
inside the shop. He didn't want to ventilate because he would lose all
his heat. Then he sprayed urethane in the same environment (probably
with just a dust mask)........................anyway, he is no longer
with us!
From personal experience, I was spraying uerthane one evening and
started to lose my peripheral vision, then I tightened up the mask and
got it back! Scary stuff, I could have passed out, alone inside a
paint booth full of stuff that can kill you. I use a resporator now,
not too expensive, $300'ish from Spruce and Specialty.
Oh, my how I have carried on and we haven't even touched on the
biggest proplem you will face. Pumping water droplets out of your
spray gun. Got to go wet sand yesterdays paint.............
JJ

JJ, you mean supplied air system, right?

The box w/ a fan that sits where the clean air is and the fan pumps the
clean air through a hose to your mask.

On Aug 25, 10:09*am, Nyal Williams wrote:
I have a very lightly used Graco HVLP spray system that I'd be willing to
sell. *It eliminates oils and moisture introduced by a compressor. *It is
complete with mask to deliver fresh, outside air under positive *pressure
to the wearer. *Write privately for details.

At 15:13 25 August 2008, PMSC Member wrote:

On Aug 25, 10:24 am, JJ Sinclair *wrote:
Brad, I wouldn't brush on the primer, half your sanding will be to
just remove the brush marks. You can get a cheap gun and compressor
for this. It is usually best to use the primer that is recommended by
the paint you are using, but most *are gray in color and this will
start to show through if (when) you get a little to heavy handed with
the wet sanding during the finishing process. That is why I use PCL
Polyprimer, because it is pure white and believe me white is the way
to go. You do need good ventilation any time your spraying anything,
not only to prevent trapping unwanted by-products in the paint, but
you don't want to be trapping any of this stuff in your lungs,
either!
That is REALLY true when using uretahne, we had a mechanic here who
recovered a Cub in the dead of winter with propane heaters running
inside the shop. He didn't want to ventilate because he would lose
all
his heat. Then he sprayed urethane in the same environment (probably
with just a dust mask)........................anyway, he is no longer
with us!
From personal experience, I was spraying uerthane one evening and
started to lose my peripheral vision, then I tightened up the mask and
got it back! Scary stuff, I could have passed out, alone inside a
paint booth full of stuff that can kill you. I use a resporator now,
not too expensive, $300'ish from Spruce and Specialty.
Oh, my how I have carried on and we haven't even touched on the
biggest proplem you will face. Pumping water droplets out of your
spray gun. Got to go wet sand yesterdays paint.............
JJ

My $0.02 on iso-cyanates and urethane paint:

Back around 1990 I painted a ship with Deltron Acrylic Urethane (PPG).
The results were great... However, I will not be doing that again.
Urethanes are simply too toxic for this amateur. *Iso-cyanates are
incredibly bad news. *How bad? *To give an idea: I walked back into my
"booth" without protection about an hour after spraying the fill coat
(K-201 iirc) on one wing and almost instantly had bronchial
constriction and a really nasty head buzz. No more than 60 seconds
exposure an hour after spraying.... *Scared the hell out of me. *If
you must do this... at least be aware of who is down wind and how
far. *If you decide to cheap out and forge ahead with a carbon filter
mask instead of a proper air-supply system, change the filters
frequently and don't wait for odor to become noticeable through the
mask, cause you'll be sorry. *Furthermore, wear the mask any -- I mean
*any* -- time the paint is open including mixing.

Take the warnings seriously.

Today's mad hatter is more likely to be an auto body guy. *Doubt me?
Go hang at the local body shop and see what you see. *There's no way
to do this stuff with zero exposure.

I've sprayed Imron and Deltron with just a chemical filter mask, but
wouldn't do it again. Interestingly enough methyl isocynate is what
was released in the Bhopal disaster. Nasty stuff.
http://www.ncbi.nlm.nih.gov/pubmed/8277516
Craig

"Brad" wrote in message
...
thanks for the comments and suggestions guys. as to the amount of gas
we burned that night, Bob K might know, it was in his shop where we
layed up the skins.............

I am leaning now towards JJ's suggestion and not go with the Prestec.
I have pretty crude painting facilities at my shop (read none) so I
hope the PPG products can tolerate a less than ideal spraying
environment.

FWIW

I sprayed a 26' boat a few years ago with AwlGrip under rather primitive
conditions - came out great.

I had a "tent" with a tarp for the floor, another tarp for the roof and
sheet plastic walls out in the middle of a gravel boat yard. I did it in
the spring when the days were warm enough, but I ran a propane heater
overnight to keep the temperature up to allow the paint to cure (lots of
moisture).

It turned out to be real easy to spray (I last painted cars back in the
'70s) - went on nice, flowed out nice. I ended up with one sag in the
finish coat (my face shield was so fogged up with overspray at the end I
really couldn't see good enough). No problems with adhesion and the boat
has been outside in the weather ever since.

Do yourself a favor and use outside air. Per the data sheets the
iso-cyanawhatever has "poor warning properties" - by the time you realize
it is coming through your mask, it is too late...

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

JJ, you mean supplied air system, right?

Yes, I have a spray booth with florescent lights, but find I need a
drop cord light also (old eyes), so I'm dragging 2 air hoses and a
drop cord. This can end up in a gigantic tangeled mess, so I have
taken to taping them all together every 3 feet or so. Works well.
Right now, I'm doing a little repair to a 26 rudder which involves
color matching old gelcoat. Gelcoat ages (oxidizes) and turnes yellow,
but when I sand out the edges of my repair I sand out the yellow and
therefor must do a color match in this 'sanded' area. I find it works
best to extend the 220 sanding a good 4 inches beyond the repair area
and then scrub down another 4 inches with abrasive cloth beyond this
area before masking off the rest of the rudder. I then spray on 3
coats, extending the paint edge an inch each pass, so that the final
paint line is at the end of the 220 sanding. The overspray is on the
scrubbed area and my masked line isn't covered with paint. 18 hours
later the overspray area can be knocked down with a few passes of 600w
up to, but not over the mask line. Then I go over the mask line with
the 800w and blend in (remove yellow) on down the rudder so as to show
a gradual blending of sanded white into non-sanded yellowish white. If
you bury the mask line with paint, it is too easy to go through the
old paint and show primer...........ugh!
I hate painting,
JJ

JJ,

You may hate painting, but I am very glad an artist like you is repairing my
ASH26E rudder . . . thanks!

bumper


"JJ Sinclair" wrote in message
...

JJ, you mean supplied air system, right?

Yes, I have a spray booth with florescent lights, but find I need a
drop cord light also (old eyes), so I'm dragging 2 air hoses and a
drop cord. This can end up in a gigantic tangeled mess, so I have
taken to taping them all together every 3 feet or so. Works well.
Right now, I'm doing a little repair to a 26 rudder which involves
color matching old gelcoat. Gelcoat ages (oxidizes) and turnes yellow,
but when I sand out the edges of my repair I sand out the yellow and
therefor must do a color match in this 'sanded' area. I find it works
best to extend the 220 sanding a good 4 inches beyond the repair area
and then scrub down another 4 inches with abrasive cloth beyond this
area before masking off the rest of the rudder. I then spray on 3
coats, extending the paint edge an inch each pass, so that the final
paint line is at the end of the 220 sanding. The overspray is on the
scrubbed area and my masked line isn't covered with paint. 18 hours
later the overspray area can be knocked down with a few passes of 600w
up to, but not over the mask line. Then I go over the mask line with
the 800w and blend in (remove yellow) on down the rudder so as to show
a gradual blending of sanded white into non-sanded yellowish white. If
you bury the mask line with paint, it is too easy to go through the
old paint and show primer...........ugh!
I hate painting,
JJ

On Aug 26, 11:43*am, "bumper" wrote:
JJ,

You may hate painting, but I am very glad an artist like you is repairing my
ASH26E rudder . . . thanks!

bumper

"JJ Sinclair" wrote in message

...





JJ, you mean supplied air system, right?

Yes, I have a spray booth with florescent lights, but find I need a
drop cord light also (old eyes), so I'm dragging 2 air hoses and a
drop cord. This can end up in a gigantic tangeled mess, so I have
taken to taping them all together every 3 feet or so. Works well.
Right now, I'm doing a little repair to a 26 rudder which involves
color matching old gelcoat. Gelcoat ages (oxidizes) and turnes yellow,
but when I sand out the edges of my repair I sand out the yellow and
therefor must do a color match in this 'sanded' area. I find it works
best to extend the 220 sanding a good 4 inches beyond the repair area
and then scrub down another 4 inches with abrasive cloth beyond this
area before masking off the rest of the rudder. I then spray on 3
coats, extending the paint edge an inch each pass, so that the final
paint line is at the end of the 220 sanding. The overspray is on the
scrubbed area and my masked line isn't covered with paint. 18 hours
later the overspray area can be knocked down with a few passes of 600w
up to, but not over the mask line. Then I go over the mask line with
the 800w and blend in (remove yellow) on down the rudder so as to show
a gradual blending of sanded white into non-sanded yellowish white. If
you bury the mask line with paint, it is too easy to go through the
old paint and show primer...........ugh!
I hate painting,
JJ- Hide quoted text -

- Show quoted text -

AMEN....
JJ's the man!
Dan Rihn
WO

On Aug 24, 9:28*am, Brad wrote:
Propane releases moisture during combustion...

Correct me if I'm wrong, but I'd expect that oxidizing propane would
only release moisture into the exhaust gasses. My heater setup vents
all of the combustion exhaust gasses outside the building. I figure
it'd have to, or else we'd all have died from CO poisioning by now.

Thanks, Bob K.

On Aug 26, 2:09*pm, Bob Kuykendall wrote:
On Aug 24, 9:28*am, Brad wrote:

Propane releases moisture during combustion...

Correct me if I'm wrong, but I'd expect that oxidizing propane would
only release moisture into the exhaust gasses. My heater setup vents
all of the combustion exhaust gasses outside the building. I figure
it'd have to, or else we'd all have died from CO poisioning by now.

Thanks, Bob K.

Was Brad using a Space Heater, or a forced air gas furnace like you
have? I wouldn't think your heater would be a problem.

On Aug 26, 4:18*pm, Uncle Fuzzy wrote:

Was Brad using a Space Heater, or a forced air gas furnace like you
have? I wouldn't think your heater would be a problem.

Brad laid up his fuselage shells at my shop, using my shop heater, not
a space heater. It's a Modine Hot Dawg 75 kbtu unit I put up several
years ago.

In the past I've used kerosene and propane space heaters, but mostly
just with quickie polyester/glass layups. Those things give me the
willies, I'm always worried about carbon monoxide poisoning.

Thanks, Bob K.

On Aug 26, 5:07*pm, Bob Kuykendall wrote:
On Aug 26, 4:18*pm, Uncle Fuzzy wrote:

Was Brad using a Space Heater, or a forced air gas furnace like you
have? I wouldn't think your heater would be a problem.

Brad laid up his fuselage shells at my shop, using my shop heater, not
a space heater. It's a Modine Hot Dawg 75 kbtu unit I put up several
years ago.

In the past I've used kerosene and propane space heaters, but mostly
just with quickie polyester/glass layups. Those things give me the
willies, I'm always worried about carbon monoxide poisoning.

Thanks, Bob K.

That's what I thought. Unfortunately, that kinda' decreases the
chances that excess moisture in the air caused the epoxy not to bond
to the gelcoat.