I sprayed a Vallejo black primer on a model and let it dry for 3 days. I just tested adhesion using 3M masking tape. Well, the tape pulled bits of the primer here and there.
I lightly thinned the V primer with distilled water (85:15) and added a drop of Flow-Aid. I sprayed at 30 psi.
Are acrylic primers supposed to be weak in adhesion? I've never had an issue with Tamiya primers.
If you have no problem with V primers, tell me how you spray!!
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Vallejo Primer Doesn't Grab Plastic Well
Chrisk-K
Joined: January 09, 2012
KitMaker: 310 posts
Armorama: 294 posts
Posted: Thursday, February 20, 2014 - 08:51 AM UTC
sheptr
Joined: May 24, 2013
KitMaker: 1 posts
Armorama: 1 posts
Posted: Thursday, February 20, 2014 - 08:59 AM UTC
Vallejo Surface Primer doesn't really grab the plastic too well. It doesn't bond at all with the plastic. I had some lifting issues as well. I use Tamiya tape to mask.
I've started to wipe down the piece I'm priming right beforehand with some 91% Isopropyl Alcohol, this seems to remove any of the mold release, oils from my hands due to assembly, etc. This has alleviated 99% of the lifting issues I had. Occasionally, a small bit will lift off. Might be user error.
I've also had success dry sanding the primer with 1000 grit, to blend these spots back in. Wet sanding will cause chunks of the primer to peel off.
Regardless, once I've finished this bottle, I'm on the hunt for another primer. I prefer working only in Acrylics, and an Acrylic primer will never have the same bite as a Lacquer based primer. Maybe the AK Interactive stuff would work better..
I've started to wipe down the piece I'm priming right beforehand with some 91% Isopropyl Alcohol, this seems to remove any of the mold release, oils from my hands due to assembly, etc. This has alleviated 99% of the lifting issues I had. Occasionally, a small bit will lift off. Might be user error.
I've also had success dry sanding the primer with 1000 grit, to blend these spots back in. Wet sanding will cause chunks of the primer to peel off.
Regardless, once I've finished this bottle, I'm on the hunt for another primer. I prefer working only in Acrylics, and an Acrylic primer will never have the same bite as a Lacquer based primer. Maybe the AK Interactive stuff would work better..
Thudius
Joined: October 22, 2012
KitMaker: 1,194 posts
Armorama: 1,077 posts
Posted: Thursday, February 20, 2014 - 09:21 AM UTC
I brush rather than spray (no airbrush) and if the primer is lifting, there is more than likely something on the surface causing it or because you're thinning with water. I was reading a build article on an other site and the guy uses thinner rather than water. He's of the opinion that using water changes the property of the primer or paint ever so slightly that it sometimes doesn't stick or gets rubbed off too easily. This does make sense. Brushing the stuff on works a treat, the slightly thicker layer you get versus sprayed on works in your favour without obscuring details and is quite durable. There is always the off chance that you have a bad batch, if you have any other primers, test them to see how they react.
Kimmo
Kimmo
didgeboy
Joined: September 21, 2010
KitMaker: 1,846 posts
Armorama: 1,509 posts
Posted: Thursday, February 20, 2014 - 09:36 AM UTC
Regular. Vallejo primer works great. Make sure you wash you kit in warm soapy water rinsand dry thoroughly before you try to prime. The surface primer worked great on my Tiran 5 build and gave nice adhesion even sprayed through the airbrush
Stickframe
#362
Joined: December 01, 2013
KitMaker: 1,661 posts
Armorama: 1,202 posts
Posted: Thursday, February 20, 2014 - 11:02 AM UTC
I've had really good luck with Vallejo Primer too - even under circumstances I know not to be that bright (sometimes over unclean/irregular surfaces). I haven't had straight primer peel off - but I have lost bits of primer + paint together. This only happened when I used the blue house painting tape for masking. Maybe there is just too much "grip"? Most of the time I mask with Tamiya yellow tape or friscket - no problems at all with either.
An odd, an sporadically occurring problem I have is when painting AK Modern US sand over Vallejo primer - the paint sometimes pools and the result is a blotchy surface - usually about half of the surface looks great, the balance leaves multiple small concentric grey/black rings? Even more weird - it doesn't happen with each AK bottle....(?) but it has happened more than 3 or 4 times...(?) if it's really obvious, repaint, if less obvious, I blend it with weathering. Any guesses on this?
I don't think it's the primer
Thanks
Nick
An odd, an sporadically occurring problem I have is when painting AK Modern US sand over Vallejo primer - the paint sometimes pools and the result is a blotchy surface - usually about half of the surface looks great, the balance leaves multiple small concentric grey/black rings? Even more weird - it doesn't happen with each AK bottle....(?) but it has happened more than 3 or 4 times...(?) if it's really obvious, repaint, if less obvious, I blend it with weathering. Any guesses on this?
I don't think it's the primer
Thanks
Nick
Petro
Joined: November 02, 2003
KitMaker: 984 posts
Armorama: 846 posts
Posted: Thursday, February 20, 2014 - 11:06 AM UTC
I too have noticed that Vallejo primer doesn't bond too well with plastic. That is with washing before hand.
As I am still new to using Vallejo products, i can say that this issue did prevent me from using masking tape on it for a camouflage pattern on my latest build.
I will continue to experiment with the products i have.
As I am still new to using Vallejo products, i can say that this issue did prevent me from using masking tape on it for a camouflage pattern on my latest build.
I will continue to experiment with the products i have.
Chrisk-K
Joined: January 09, 2012
KitMaker: 310 posts
Armorama: 294 posts
Posted: Thursday, February 20, 2014 - 11:10 AM UTC
Do you need to wet the surface? I applied a thin coat. Maybe, that's the culprit. Most of lifting took place at the edges. Hmm...
Or, maybe I should have not thinned the primer. I always wipe the model with a Plastic Prep, so I don't think there was an issue with the surface.
I've bought six 60 ml bottles, so I hope Vallejo primers work for me!
Or, maybe I should have not thinned the primer. I always wipe the model with a Plastic Prep, so I don't think there was an issue with the surface.
I've bought six 60 ml bottles, so I hope Vallejo primers work for me!
Thudius
Joined: October 22, 2012
KitMaker: 1,194 posts
Armorama: 1,077 posts
Posted: Thursday, February 20, 2014 - 12:02 PM UTC
Quoted Text
Do you need to wet the surface? I applied a thin coat. Maybe, that's the culprit. Most of lifting took place at the edges. Hmm...
Or, maybe I should have not thinned the primer. I always wipe the model with a Plastic Prep, so I don't think there was an issue with the surface.
I've bought six 60 ml bottles, so I hope Vallejo primers work for me!
Aha! I think I found your problem. If it's peeling at the edges, then you didn't give it good coverage. Vallejo primers actually form a skin, which is good news/bad news. Make sure you get good a good coat or two everywhere. The problems I've had with primer rubbing off easily has been due to poor coverage. I've been using Vallejos for a little over a year, and once you figure out how they work, you'll love them. The primers are great for attaching/sealing pe and are a lot more economical in the larger bottles versus the 17ml droppers. The one thing they don't do well is sand unless its well cured and using very very fine grits only.
Kimmo
SdAufKla
Joined: May 07, 2010
KitMaker: 2,238 posts
Armorama: 2,158 posts
Posted: Thursday, February 20, 2014 - 02:55 PM UTC
Just using water to reduce the paint may have contributed to your problem.
Water-based acrylics really should have some acrylic medium added back in when they are diluted. The acrylic medium is what binds ("glues") the pigment to the surface, and if there's not enough binder in the paint solution, when the paint dries, it might not adhere well. This is a problem that's really prevalent in airbrushed water-based acrylic paints.
Vallejo makes a Model Color Thinning Medium and a Model Air Thinning Medium which are both formulated to add back the acrylic binders necessary to adhere the paint to the surface.
I have found that the Model Air Thinning Medium works well by itself for reducing both Model Air and Model Colors for airbrushing.
For hand brushing, I mix the Model Color Thinning Medium half-and-half with water. This is totally a measure of economy for me, as I have found that it's not necessary for me to use straight Vallejo Thinning Medium for brush painting (and the thinner costs as much as the paint). However, using straight Model Color Thinning Medium works totally fine.
Anyways, adding back some acrylic binder into your paint reduced for airbrushing might resolve your adhesion issues.
HTH,
Water-based acrylics really should have some acrylic medium added back in when they are diluted. The acrylic medium is what binds ("glues") the pigment to the surface, and if there's not enough binder in the paint solution, when the paint dries, it might not adhere well. This is a problem that's really prevalent in airbrushed water-based acrylic paints.
Vallejo makes a Model Color Thinning Medium and a Model Air Thinning Medium which are both formulated to add back the acrylic binders necessary to adhere the paint to the surface.
I have found that the Model Air Thinning Medium works well by itself for reducing both Model Air and Model Colors for airbrushing.
For hand brushing, I mix the Model Color Thinning Medium half-and-half with water. This is totally a measure of economy for me, as I have found that it's not necessary for me to use straight Vallejo Thinning Medium for brush painting (and the thinner costs as much as the paint). However, using straight Model Color Thinning Medium works totally fine.
Anyways, adding back some acrylic binder into your paint reduced for airbrushing might resolve your adhesion issues.
HTH,
Grauwolf
#084
Joined: September 14, 2005
KitMaker: 2,485 posts
Armorama: 743 posts
Posted: Thursday, February 20, 2014 - 03:47 PM UTC
Tamiya primer is chemically a solvent based product that bites into the plastic and
provides a resistant surface, with tooth on to which other paints will grab both
brushed or AB'ed.
Vallejo, AK and the likes are vinyl,polyurethane based products
a little like white glue(PVC) with color in it.
They create a skin that bonds.
So these paints basically stick to the plastic but don't bite.
Thinning must be done with the proper thinners so that they
maintain their adhesion properties as explained by Mike.
If you thin with water, you are destroying the true adhesion properties
of the base coat and subsequent coats.
Most water based paints are actually not designed for plastic but can
be used on it.
Many labels will read "water clean up"....essentially meaning that
water breaks down these paints and their adherence rendering easy clean up
and should not be mistaken with "thin" with water.
Personally, as far as primer goes, I use TAMIYA....it bites, has tooth,
fills scratches and sands well.
Cheers,
Joe
provides a resistant surface, with tooth on to which other paints will grab both
brushed or AB'ed.
Vallejo, AK and the likes are vinyl,polyurethane based products
a little like white glue(PVC) with color in it.
They create a skin that bonds.
So these paints basically stick to the plastic but don't bite.
Thinning must be done with the proper thinners so that they
maintain their adhesion properties as explained by Mike.
If you thin with water, you are destroying the true adhesion properties
of the base coat and subsequent coats.
Most water based paints are actually not designed for plastic but can
be used on it.
Many labels will read "water clean up"....essentially meaning that
water breaks down these paints and their adherence rendering easy clean up
and should not be mistaken with "thin" with water.
Personally, as far as primer goes, I use TAMIYA....it bites, has tooth,
fills scratches and sands well.
Cheers,
Joe
Chrisk-K
Joined: January 09, 2012
KitMaker: 310 posts
Armorama: 294 posts
Posted: Thursday, February 20, 2014 - 04:07 PM UTC
From Vallejo FAQs:
7.3. Can I dilute the new Acrylic-Polyurethane Primers for use in an airbrush? They seem thicker than Model Air.
The new acrylic-polyurethane primers are especially formulated for use in air brushing. The special quality, the polyurethane component, which gives it the strength and the resistance to nicks and scratches, will be diminished by diluting the product, but the product can be diluted with our Thinner or even with distilled water. To maintain its special qualities, the less dilution the better.
-------------
So diluting with distilled water is OK.
7.3. Can I dilute the new Acrylic-Polyurethane Primers for use in an airbrush? They seem thicker than Model Air.
The new acrylic-polyurethane primers are especially formulated for use in air brushing. The special quality, the polyurethane component, which gives it the strength and the resistance to nicks and scratches, will be diminished by diluting the product, but the product can be diluted with our Thinner or even with distilled water. To maintain its special qualities, the less dilution the better.
-------------
So diluting with distilled water is OK.
Grauwolf
#084
Joined: September 14, 2005
KitMaker: 2,485 posts
Armorama: 743 posts
Posted: Thursday, February 20, 2014 - 05:08 PM UTC
Yes you can but you're changing the properties of the paint.
Diminished resistance as they clearly state.
Diminished resistance as they clearly state.
Venko555
Joined: December 07, 2013
KitMaker: 908 posts
Armorama: 698 posts
Posted: Thursday, February 20, 2014 - 05:55 PM UTC
I think AK primers are better than Vallejo, but it's personal opinion. Very good bite and they are sandable and don't peel off. I have Vallejo grey primer, but had problems too. And I prefer to work with acrylic. Alclad primers are superb also, but they are cellulose 
brian638
Joined: July 24, 2004
KitMaker: 318 posts
Armorama: 263 posts
Posted: Thursday, February 20, 2014 - 09:19 PM UTC
Hi I use Vallejo Surface Primers for all my models and figures. The one thing I never do is thin them. I always use them straight in the brush.
The only time I've had issues with paint lifting is when I hadn't cleaned a resin figure, so my own fault. I have found that dependant on the temperature I may alter the spray pressure too.
I hope this helps
Brian
The only time I've had issues with paint lifting is when I hadn't cleaned a resin figure, so my own fault. I have found that dependant on the temperature I may alter the spray pressure too.
I hope this helps
Brian
mvaiano
Joined: January 24, 2012
KitMaker: 1,054 posts
Armorama: 1,050 posts
Posted: Thursday, February 20, 2014 - 10:41 PM UTC
russamotto
Joined: December 14, 2007
KitMaker: 3,389 posts
Armorama: 2,054 posts
Posted: Friday, February 21, 2014 - 01:45 AM UTC
I have used the new acrylic polyurethane primer straight from the bottle, and had no issues. However, it needs to fully cure, which can take 2-3 days depending on climate conditions.
Tojo72
Joined: June 06, 2006
KitMaker: 4,691 posts
Armorama: 3,509 posts
Posted: Friday, February 21, 2014 - 03:00 AM UTC
It seems like this Vallejo Primer is more trouble then i's worth.I mean with all these ratios,sanding,surface prep,that have been talked about,why use it ? Just wondering
I just spray on Tamiya Fine or Mr Surfacer 1200 with no issues
I just spray on Tamiya Fine or Mr Surfacer 1200 with no issues
Thudius
Joined: October 22, 2012
KitMaker: 1,194 posts
Armorama: 1,077 posts
Posted: Friday, February 21, 2014 - 06:06 AM UTC
Quoted Text
It seems like this Vallejo Primer is more trouble then i's worth.I mean with all these ratios,sanding,surface prep,that have been talked about,why use it ? Just wondering
I just spray on Tamiya Fine or Mr Surfacer 1200 with no issues
Some of us don't have the luxury of being able to use solvent based paints. You work with what you got or what you can with. All acrylics take some getting used to, I keep reading of people having loads of trouble spraying with enamels and lacquers too, so it's not a mutually exclusive problem.
Chrisk-K
Joined: January 09, 2012
KitMaker: 310 posts
Armorama: 294 posts
Posted: Friday, February 21, 2014 - 06:17 AM UTC
Although I can surely spray solvent-based paints, I prefer to spray acrylics. I do have a spray booth, but if I leave the window open in winter to exhaust fumes, my room temperature will drop to 30-40F in no time, and such a low temperature will cause other problems.
johhar
Joined: September 22, 2008
KitMaker: 476 posts
Armorama: 447 posts
Posted: Friday, February 21, 2014 - 06:56 AM UTC
How does one wash a finished kit in warm soapy water and rinse it without potentially damaging fragile detail?
I can't imagine submerging a finished Dragon halftrack or full skirted Pz or Stug III/IV in soapy water and then using whatever water pressure is necessary to rinse it.
Thanks,
Jon
I can't imagine submerging a finished Dragon halftrack or full skirted Pz or Stug III/IV in soapy water and then using whatever water pressure is necessary to rinse it.
Thanks,
Jon
Chrisk-K
Joined: January 09, 2012
KitMaker: 310 posts
Armorama: 294 posts
Posted: Friday, February 21, 2014 - 07:49 AM UTC
Submerge a model in a warm soapy water and leave it for a few minutes. Then, rinse it with a kitchen sprayer.
Or, wipe a model with IPA or Plastic Prep using a wide "make-up" brush.
Or, wipe a model with IPA or Plastic Prep using a wide "make-up" brush.
chumpo
Joined: August 30, 2010
KitMaker: 749 posts
Armorama: 521 posts
Posted: Friday, February 21, 2014 - 08:35 AM UTC
Quoted Text
Quoted TextIt seems like this Vallejo Primer is more trouble then i's worth.I mean with all these ratios,sanding,surface prep,that have been talked about,why use it ? Just wondering
I just spray on Tamiya Fine or Mr Surfacer 1200 with no issues
Some of us don't have the luxury of being able to use solvent based paints. You work with what you got or what you can with. All acrylics take some getting used to, I keep reading of people having loads of trouble spraying with enamels and lacquers too, so it's not a mutually exclusive problem.
But the Mr Surfacer's are just so nice and they adhere so good , but then they smell to the high heavens .
Thudius
Joined: October 22, 2012
KitMaker: 1,194 posts
Armorama: 1,077 posts
Posted: Friday, February 21, 2014 - 09:25 AM UTC
[/quote]But the Mr Surfacer's are just so nice and they adhere so good , but then they smell to the high heavens .[/quote]
Yup. My work bench is the dining room table so everything gets packed up after a session and I brush paint. That means no stinking up the joint and everything has to dry immediately. I'm more than happy with the Vallejos and every time I use them, I get more familiar with what you can and can't do with them. In some ways they're superior to enamels and oils, in some ways, not. But there are work arounds for virtually every technique and application. Still trying to figure out feathered edges, I think the answer is in make-up sponges.
Kimmo
Yup. My work bench is the dining room table so everything gets packed up after a session and I brush paint. That means no stinking up the joint and everything has to dry immediately. I'm more than happy with the Vallejos and every time I use them, I get more familiar with what you can and can't do with them. In some ways they're superior to enamels and oils, in some ways, not. But there are work arounds for virtually every technique and application. Still trying to figure out feathered edges, I think the answer is in make-up sponges.
Kimmo
chumpo
Joined: August 30, 2010
KitMaker: 749 posts
Armorama: 521 posts
Posted: Friday, February 21, 2014 - 10:04 AM UTC
I never gave what you just said any thought . I tried to airbrush Vallejo model color and model air and I failed miserably . Their only redeeming quality is they brush paint nice and it's not just me but other guys at the hobby shop , we all had the same experience with Vallejo . You are doing a banged up job with those paintbrushes . Now what about Lifecolor ?
Thudius
Joined: October 22, 2012
KitMaker: 1,194 posts
Armorama: 1,077 posts
Posted: Friday, February 21, 2014 - 12:25 PM UTC
Quoted Text
I never gave what you just said any thought . I tried to airbrush Vallejo model color and model air and I failed miserably . Their only redeeming quality is they brush paint nice and it's not just me but other guys at the hobby shop , we all had the same experience with Vallejo . You are doing a banged up job with those paintbrushes . Now what about Lifecolor ?
Lifecolor brushes well too, but Vallejos cover better. A little patience and a lot of practice goes a long way
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