Hi all
I brush paint models with acrylics and so i use a spray primer first so the paint sticks. CUrrently im using Plasti-Kote white spray paint (cos it was cheap) but it goes on and it makes the plastic more brittle, this is especially apparent and annoying with little pieces like undercarriage struts cos they break.
Does anyone else have this problem or know a way to get round it with a different spray primer?
Cheers
Rich
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spray primer makes the plastic brittle
RichPrag
England - South West, United Kingdom
Joined: September 24, 2007
KitMaker: 26 posts
AeroScale: 24 posts
Joined: September 24, 2007
KitMaker: 26 posts
AeroScale: 24 posts
Posted: Monday, September 14, 2009 - 12:05 AM UTC
Posted: Monday, September 14, 2009 - 12:27 AM UTC
Hi Rich
Hmm, never had such a problem. Maybe you applied too much primer that it solved the plastic which weakend it ultimately? Of course this stuff is designed to attack the plastic to make a good bond with the surface but I never heard of a problem like you had.
Did you glue wich CA and maybe activatior? this stuff destroys plastic if not applied very carefully (ask me how I know ...) .. another reason why I avoid CA as much as I can.
hope you can get replacement parts ..
all the best
Steffen
Hmm, never had such a problem. Maybe you applied too much primer that it solved the plastic which weakend it ultimately? Of course this stuff is designed to attack the plastic to make a good bond with the surface but I never heard of a problem like you had.
Did you glue wich CA and maybe activatior? this stuff destroys plastic if not applied very carefully (ask me how I know ...) .. another reason why I avoid CA as much as I can.
hope you can get replacement parts ..
all the best
Steffen
RichPrag
England - South West, United Kingdom
Joined: September 24, 2007
KitMaker: 26 posts
AeroScale: 24 posts
Joined: September 24, 2007
KitMaker: 26 posts
AeroScale: 24 posts
Posted: Monday, September 14, 2009 - 01:18 AM UTC
Hi Steffen
Could be that i applied too much primer, ill have to exeperiment with differing levels i think.
Whats CA? I use revell poly cement (i thinkits called that) to glue and sometimes superglue
Could be that i applied too much primer, ill have to exeperiment with differing levels i think.
Whats CA? I use revell poly cement (i thinkits called that) to glue and sometimes superglue
Posted: Monday, September 14, 2009 - 01:23 AM UTC
Hi Rich
CA is cyanoacrylate ... widely known as super glue ... together with the acellerator it really destroys the plastic (but this depends on the plastic used).
all the best
Steffen
CA is cyanoacrylate ... widely known as super glue ... together with the acellerator it really destroys the plastic (but this depends on the plastic used).
all the best
Steffen
Posted: Monday, September 14, 2009 - 06:10 AM UTC
Hi Rich
I've never heard of the problem you describe either. I think Plasti-Kote is an acrylic paint, so it shouldn't attack the plastic at all. Alternatives? I have used Halford's grey, white and the yellow "filler" primers on various projects in the past with no ill effects.
All the best
Rowan
I've never heard of the problem you describe either. I think Plasti-Kote is an acrylic paint, so it shouldn't attack the plastic at all. Alternatives? I have used Halford's grey, white and the yellow "filler" primers on various projects in the past with no ill effects.
All the best
Rowan
Posted: Monday, September 14, 2009 - 09:13 AM UTC
Unless they have changed the formula plasti-cote paints use to be cellulose based (well they were when I last used them a few years ago) which could explain the brittleness as the cellulose eats the plastic.
Halford's primers are my choice I've even used the red "oxide" primer before with no problems and they're only a couple of quid more than the plasti-cote primers.
Halford's primers are my choice I've even used the red "oxide" primer before with no problems and they're only a couple of quid more than the plasti-cote primers.
Posted: Monday, September 14, 2009 - 09:26 AM UTC
Hi Allen
The Plasti-Kote paints that I've used are described as "acrylic enamels" and certainly don't smell like celulose paints. But, whatever, I've used celulose paints for years and they've never made styrene brittle in my experience. Yes, they "eat" it if applied incorrectly (i.e.brushed on and worked over), but brittle? No.
All the best
Rowan
The Plasti-Kote paints that I've used are described as "acrylic enamels" and certainly don't smell like celulose paints. But, whatever, I've used celulose paints for years and they've never made styrene brittle in my experience. Yes, they "eat" it if applied incorrectly (i.e.brushed on and worked over), but brittle? No.
All the best
Rowan
stonar
England - West Midlands, United Kingdom
Joined: August 15, 2008
KitMaker: 337 posts
AeroScale: 309 posts
Joined: August 15, 2008
KitMaker: 337 posts
AeroScale: 309 posts
Posted: Wednesday, September 16, 2009 - 06:13 AM UTC
Quoted Text
Hi Rich
I have used Halford's grey, white and the yellow "filler" primers on various projects in the past with no ill effects.
Ditto
Steve
RichPrag
England - South West, United Kingdom
Joined: September 24, 2007
KitMaker: 26 posts
AeroScale: 24 posts
Joined: September 24, 2007
KitMaker: 26 posts
AeroScale: 24 posts
Posted: Tuesday, September 22, 2009 - 02:15 AM UTC
thanks for the replies everyone, useful stuff. Ive been looking at this some more and what i know think is that the primer ends up being thicker than some of the parts. I guess this makes the piece have more weight overall than the plastic can cope with...
When do you guys prime all the fiddly bits like landing gear struts? I have been spraying the complete sprues before i take any pieces off up til now. And also i have to prime things cos i brush paint with those revell aqua acrylics.
Rich
When do you guys prime all the fiddly bits like landing gear struts? I have been spraying the complete sprues before i take any pieces off up til now. And also i have to prime things cos i brush paint with those revell aqua acrylics.
Rich