Media Blasting


Bill Welch
 

I think Dennis meant Harbor Freight instead of "Horrid Freight."

I have used baking soda in the summer in Virginia with good results. I was using it outside. I liked it as it was cheap and easy to control. It will not touch brass but I used vinegar to etch this.

Regarding using media blasting instead of paint stripper, I am not a chemist but somehow I just think putting such a powerful chemical, whatever it is, on styrene cannot be good for the styrene in the long run. And let me tell, you do not want to use Chameleon paint stripper with resin. You do not want to know how I know this.

Bill Welch


Frederick Freitas <prrinvt@...>
 

GUYZ,
 
           Bill must be talking about the FGEX truss rod reefer that has sagged to the railhead. And all this time I thought he built it that way. Great scenery for the repair yard.
 
Fred Freitas
 
ducking for cover

--- On Wed, 11/11/09, Bill Welch <fgexbill@tampabay.rr.com> wrote:


From: Bill Welch <fgexbill@tampabay.rr.com>
Subject: [STMFC] Media Blasting
To: STMFC@yahoogroups.com
Date: Wednesday, November 11, 2009, 10:34 PM


 



I think Dennis meant Harbor Freight instead of "Horrid Freight."

I have used baking soda in the summer in Virginia with good results.
I was using it outside. I liked it as it was cheap and easy to
control. It will not touch brass but I used vinegar to etch this.

Regarding using media blasting instead of paint stripper, I am not a
chemist but somehow I just think putting such a powerful chemical,
whatever it is, on styrene cannot be good for the styrene in the long
run. And let me tell, you do not want to use Chameleon paint stripper
with resin. You do not want to know how I know this.

Bill Welch


Gatwood, Elden J SAD
 

I would also avoid using media blasting using "grit", even the fine stuff, on
resin, without watching VERY closely what it is doing to the surface. I
tried to remove badly applied acrylic paint from a Westy G22, and while the
acrylic blobs gradually came off, the surrounding unpainted resin was badly
scoured and pitted.

Elden Gatwood

-----Original Message-----
From: STMFC@yahoogroups.com [mailto:STMFC@yahoogroups.com] On Behalf Of Bill
Welch
Sent: Wednesday, November 11, 2009 10:34 PM
To: STMFC@yahoogroups.com
Subject: [STMFC] Media Blasting



I think Dennis meant Harbor Freight instead of "Horrid Freight."

I have used baking soda in the summer in Virginia with good results.
I was using it outside. I liked it as it was cheap and easy to control. It
will not touch brass but I used vinegar to etch this.

Regarding using media blasting instead of paint stripper, I am not a chemist
but somehow I just think putting such a powerful chemical, whatever it is, on
styrene cannot be good for the styrene in the long run. And let me tell, you
do not want to use Chameleon paint stripper with resin. You do not want to
know how I know this.

Bill Welch


jerryglow2
 

I probably would not use it for paint removal on resin but do routinely hit the whole model prior to painting. Ted Culotta's articles almost universally mention doing this regardless of the material of the model.

Jerry Glow

--- In STMFC@yahoogroups.com, "Gatwood, Elden J SAD " <elden.j.gatwood@...> wrote:

I would also avoid using media blasting using "grit", even the fine stuff, on
resin, without watching VERY closely what it is doing to the surface. I
tried to remove badly applied acrylic paint from a Westy G22, and while the
acrylic blobs gradually came off, the surrounding unpainted resin was badly
scoured and pitted.

Elden Gatwood

-----Original Message-----
From: STMFC@yahoogroups.com [mailto:STMFC@yahoogroups.com] On Behalf Of Bill
Welch
Sent: Wednesday, November 11, 2009 10:34 PM
To: STMFC@yahoogroups.com
Subject: [STMFC] Media Blasting



I think Dennis meant Harbor Freight instead of "Horrid Freight."

I have used baking soda in the summer in Virginia with good results.
I was using it outside. I liked it as it was cheap and easy to control. It
will not touch brass but I used vinegar to etch this.

Regarding using media blasting instead of paint stripper, I am not a chemist
but somehow I just think putting such a powerful chemical, whatever it is, on
styrene cannot be good for the styrene in the long run. And let me tell, you
do not want to use Chameleon paint stripper with resin. You do not want to
know how I know this.

Bill Welch


Gatwood, Elden J SAD
 

Yes, I should have tried other means to remove that "paint". Unfortunately,
it adhered extremely well to certain portions, leaving others bare. Repeated
passes with the tool actually bagan to remove the rivets in the center of the
paint blobs, at which time I stopped. Examination of the surfaces around the
paint blobs showed considerable erosion of the surface.

Simple surface etching for paint adhesion causes no problems.

Elden Gatwood

-----Original Message-----
From: STMFC@yahoogroups.com [mailto:STMFC@yahoogroups.com] On Behalf Of
jerryglow@comcast.net
Sent: Thursday, November 12, 2009 9:00 AM
To: STMFC@yahoogroups.com
Subject: [STMFC] Re: Media Blasting



I probably would not use it for paint removal on resin but do routinely hit
the whole model prior to painting. Ted Culotta's articles almost universally
mention doing this regardless of the material of the model.

Jerry Glow

--- In STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com> , "Gatwood,
Elden J SAD " <elden.j.gatwood@...> wrote:

I would also avoid using media blasting using "grit", even the fine
stuff, on resin, without watching VERY closely what it is doing to the
surface. I tried to remove badly applied acrylic paint from a Westy
G22, and while the acrylic blobs gradually came off, the surrounding
unpainted resin was badly scoured and pitted.

Elden Gatwood

-----Original Message-----
From: STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com>
[mailto:STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com> ] On
Behalf Of Bill Welch
Sent: Wednesday, November 11, 2009 10:34 PM
To: STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com>
Subject: [STMFC] Media Blasting



I think Dennis meant Harbor Freight instead of "Horrid Freight."

I have used baking soda in the summer in Virginia with good results.
I was using it outside. I liked it as it was cheap and easy to
control. It will not touch brass but I used vinegar to etch this.

Regarding using media blasting instead of paint stripper, I am not a
chemist but somehow I just think putting such a powerful chemical,
whatever it is, on styrene cannot be good for the styrene in the long
run. And let me tell, you do not want to use Chameleon paint stripper
with resin. You do not want to know how I know this.

Bill Welch


pullmanboss <tgmadden@...>
 

Elden wrote:

Yes, I should have tried other means to remove that "paint". Unfortunately,
it adhered extremely well to certain portions, leaving others bare. Repeated
passes with the tool actually bagan to remove the rivets in the center of the
paint blobs, at which time I stopped. Examination of the surfaces around the
paint blobs showed considerable erosion of the surface.
Abrasive blasting doesn't work well on resilient materials. I'm not a metallurgist and am probably using the wrong words to describe properties, but take solder on brass. Solder is softer than brass, but both are rigid materials. Grit blasting will erode the solder much faster than the brass. But paint on resin is different - particularly pockets of thick, residual paint left after chemical stripping. The paint is softer than the resin, but it may be more resilient - recoiling under the pressure of the grit blast and rebounding to bounce the grit off rather than being abraded.

As I say, there must be better terms to describe the properties of the various materials and surfaces, but I hope you get the idea.....

Tom Madden


golden1014
 

Gentlemen,

There are two factors with grit blasting. One is the media, the other is the blast pressure. If you use 120 psi you're going to blast off everything in sight. I grit-blast almost everything with fine blast media in the 60-80 psi range. I even weather models with it. In my opinion, if your modeling emphasis is freight car construction, a grit blaster is an indispensible tool.

John Golden
Bloomington, IN

--- In STMFC@yahoogroups.com, "Gatwood, Elden J SAD " <elden.j.gatwood@...> wrote:

Yes, I should have tried other means to remove that "paint". Unfortunately,
it adhered extremely well to certain portions, leaving others bare. Repeated
passes with the tool actually bagan to remove the rivets in the center of the
paint blobs, at which time I stopped. Examination of the surfaces around the
paint blobs showed considerable erosion of the surface.

Simple surface etching for paint adhesion causes no problems.

Elden Gatwood

-----Original Message-----
From: STMFC@yahoogroups.com [mailto:STMFC@yahoogroups.com] On Behalf Of
jerryglow@...
Sent: Thursday, November 12, 2009 9:00 AM
To: STMFC@yahoogroups.com
Subject: [STMFC] Re: Media Blasting



I probably would not use it for paint removal on resin but do routinely hit
the whole model prior to painting. Ted Culotta's articles almost universally
mention doing this regardless of the material of the model.

Jerry Glow

--- In STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com> , "Gatwood,
Elden J SAD " <elden.j.gatwood@> wrote:

I would also avoid using media blasting using "grit", even the fine
stuff, on resin, without watching VERY closely what it is doing to the
surface. I tried to remove badly applied acrylic paint from a Westy
G22, and while the acrylic blobs gradually came off, the surrounding
unpainted resin was badly scoured and pitted.

Elden Gatwood

-----Original Message-----
From: STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com>
[mailto:STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com> ] On
Behalf Of Bill Welch
Sent: Wednesday, November 11, 2009 10:34 PM
To: STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com>
Subject: [STMFC] Media Blasting



I think Dennis meant Harbor Freight instead of "Horrid Freight."

I have used baking soda in the summer in Virginia with good results.
I was using it outside. I liked it as it was cheap and easy to
control. It will not touch brass but I used vinegar to etch this.

Regarding using media blasting instead of paint stripper, I am not a
chemist but somehow I just think putting such a powerful chemical,
whatever it is, on styrene cannot be good for the styrene in the long
run. And let me tell, you do not want to use Chameleon paint stripper
with resin. You do not want to know how I know this.

Bill Welch


Gatwood, Elden J SAD
 

John;

I also like my blaster, but I just learned the hard way not to spend too much
time in one place on a resin kit.

Elden Gatwood

-----Original Message-----
From: STMFC@yahoogroups.com [mailto:STMFC@yahoogroups.com] On Behalf Of John
Sent: Thursday, November 12, 2009 1:02 PM
To: STMFC@yahoogroups.com
Subject: [STMFC] Re: Media Blasting



Gentlemen,

There are two factors with grit blasting. One is the media, the other is the
blast pressure. If you use 120 psi you're going to blast off everything in
sight. I grit-blast almost everything with fine blast media in the 60-80 psi
range. I even weather models with it. In my opinion, if your modeling
emphasis is freight car construction, a grit blaster is an indispensible
tool.

John Golden
Bloomington, IN

--- In STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com> , "Gatwood,
Elden J SAD " <elden.j.gatwood@...> wrote:

Yes, I should have tried other means to remove that "paint".
Unfortunately, it adhered extremely well to certain portions, leaving
others bare. Repeated passes with the tool actually bagan to remove
the rivets in the center of the paint blobs, at which time I stopped.
Examination of the surfaces around the paint blobs showed considerable
erosion of the surface.

Simple surface etching for paint adhesion causes no problems.

Elden Gatwood

-----Original Message-----
From: STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com>
[mailto:STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com> ] On Behalf
Of jerryglow@...
Sent: Thursday, November 12, 2009 9:00 AM
To: STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com>
Subject: [STMFC] Re: Media Blasting



I probably would not use it for paint removal on resin but do
routinely hit the whole model prior to painting. Ted Culotta's
articles almost universally mention doing this regardless of the material
of the model.

Jerry Glow

--- In STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com>
<mailto:STMFC%40yahoogroups.com> , "Gatwood, Elden J SAD "
<elden.j.gatwood@> wrote:

I would also avoid using media blasting using "grit", even the fine
stuff, on resin, without watching VERY closely what it is doing to
the surface. I tried to remove badly applied acrylic paint from a
Westy G22, and while the acrylic blobs gradually came off, the
surrounding unpainted resin was badly scoured and pitted.

Elden Gatwood

-----Original Message-----
From: STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com>
<mailto:STMFC%40yahoogroups.com> [mailto:STMFC@yahoogroups.com
<mailto:STMFC%40yahoogroups.com> <mailto:STMFC%40yahoogroups.com> ]
On Behalf Of Bill Welch
Sent: Wednesday, November 11, 2009 10:34 PM
To: STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com>
<mailto:STMFC%40yahoogroups.com>
Subject: [STMFC] Media Blasting



I think Dennis meant Harbor Freight instead of "Horrid Freight."

I have used baking soda in the summer in Virginia with good results.
I was using it outside. I liked it as it was cheap and easy to
control. It will not touch brass but I used vinegar to etch this.

Regarding using media blasting instead of paint stripper, I am not a
chemist but somehow I just think putting such a powerful chemical,
whatever it is, on styrene cannot be good for the styrene in the
long run. And let me tell, you do not want to use Chameleon paint
stripper with resin. You do not want to know how I know this.

Bill Welch