Removing excess enamel wash is removing underlying acrylic layers too and I don't know why

Looks to me you got the products and order correct. Acrylic color coat, then two acrylic clear coats for the decal work, then enamel products for panel line accents and cleanup.

All I can think of is how long did you let the acrylic clear coats cure?

Sorry you have having this trouble. Don't worry, somebody will help figure this out if I'm on the wrong track here.

Thanks Greg. The first time around I left the X-22 to cure overnight but for yesterday's test (with the two fine coats of Klear) I only waited a couple of hours so perhaps I was jumping the gun.

I've primed and painted two other scraps with panel lines and was planning on Klear-coating them this evening. Any suggestions on how long I should wait before applying enamel washes? Thanks again.

I'm thinking mineral spirits might be milder and also don't soak your cleaning cloth or what ever you are using. You just want it damp but not soaking wet. I'm not sure what Testors has in their thinner blend these days but it may have some lacquer thinner in it, thus the problem.

I find that Testors' enamel thinner also removes Testors' Metalizer paints, eventhough the paints are lacquer paints.

The fact that you needed to remove some wash suggests that you try to apply a lot less to begin with.

And use really mild thinner like turpenoid for the wiping.

Two thoughts come to mind. 1, how long did you allow for the acrylics to dry and cure? 2, what method are you using to remove the excess wash? Too much pressure on acrylic paints that have not had enough time to dry and cure will remove them. Simple handling of uncured paints will remove them from handled areas.

That seems like a lot of paint coats in a short time to me, but then I am a very slow builder so my opinion might be skewed. If your paint coats are thin, maybe you are ok but it you are heavy-handed with the airbrush like me, I think you might want to consider longer dry times.

In your OP you mentioned using Tamiya clear coat, in your last post you typed "Klear". I'm a little confused.

The is the second post here in 2 days regarding a solvent-based thinner damaging an underlying Tamiya acrylic coat. I don't use a lot of Tamiya, and I hope somebody with Tamiya experience will chime in. I regularly use home made enamal wash made with Testors enamels and Testors enamel thinner over acrylic clear coats without problems, but I've never done it over the top of any Tamiya acrylic product.

Thanks Greg. Originally I used Tamiya X-22 on the Spitfire but after encountering the problem I decided to try Klear as so many others rave about it (I'm actually using "Revive" which is newer version of it).

The good news is that the mineral spirits worked much better. I let the two coats of Klear (Revive) dry for over 24 hours and none of the underlying paint layers were affected when I removed the excess Tamiya Panel Line Accent. The only negative was that the capillary action on the panel lines was not as good as it was when using the X-22. I suspect my two coats may have been a little heavy for the tiny panel lines on a 1/72 aircraft. This made the clean up a bit tricky and the results aren't quite as good as I had hoped but good enough. When I do the topside of the aircraft I'm only going to use a single coat of Klear and let it dry over the weekend.

Thanks to everyone for their help.

Happy to hear you are making progress.

 I think it's safe to say go back to X 22 now that you see mineral spirits works and doesn't hurt acrylic clears. You can always test it on a sprue if you're unsure. I already know it's safe but you may need to prove that to yourself. To me testing is more fun than building lol !

I have found x-22 is not a good clear coat if you use enamel washes. It will do just what happened to you.. I suggest mr. hobby GX100 Super Clear III, Alclad clear coat or johnson's klear.

Testing can be fun ... this afternoon I experimented with what happens when you forget to replace the nozzle after cleaning an airbrush.  Luckily I use a spray booth and so the collatoral damage was minimal. Lesson learned!

I think I'm going to try one coat of Klear rather than two and see what happens.

Jakealoo

Thanks ... my replies to everyone's responses are being moderated and so the answer to the first question (which was asked earlier today) hasn't appeared yet. I'm in the process of doing another test where I left the Tamiya Fine Scale Primer to dry for 30 minutes before applying a layer of Tamiya acrylic. I left that for several hours before applying two coats of Klear which I'm leaving to cure for at least 24 hours. I've been using a cotton bud lightly soaked in thinner. I may have pressed too hard the first time I attempted to remove the excess pin wash (from the 1/72 Spitfire) but on my second test I was very careful not to apply too much pressure but obviously not careful enough (unless the Testors is to blame). On the current test I will use mineral spirits and go easy on the cotton bud. Thanks again.

 

I like to let any primer coat dry and cure overnite before any next colors are applied on top of the primer. If you’re only waiting at most a couple of hours, that does not give anything time to cure, only time to be surface dry. 

Jakealoo

I left the Tamiya Fine Scale Primer to dry for 30 minutes before applying a layer of Tamiya acrylic. I left that for several hours before applying two coats of Klear which I'm leaving to cure for at least 24 hours.

I'd have left the primer for 12 hours before applying the colour coat, then another 12 hours before applying the clear coat, which then should be left for 12-18 hours.

As Stik said, Tamiya acrylics are touch-dry in minutes when airbrushed, but are still soft for some hours before they're fully cured.

Applying the clear coat over it all further increases the curing time as it adds a more or less impermeable layer which blocks exposure to oxygen, which is required for the curing process.

modelmaker66

I have found x-22 is not a good clear coat if you use enamel washes.

I was wondering. Thank you for posting that.

Thanks Stikpusher and Phil_H ... I will increase the drying times as you suggest. Some of the paint manufacturers imply that the first coat can be applied just minutes after using their primer but perhaps that's just a means of increasing sales. I recently picked up a bottle of Stynylrez "Easy App Surface Primer" and it says "Let dry 5 to 8 minutes (3 minutes if dried with an artifical heat source)". Nevertheless I will follow your advice.

Jakealoo

Some of the paint manufacturers imply that the first coat can be applied just minutes after using their primer

In your case, Tamiya's Surface Primer, whether it be in the spray can or a 40ml jar, is a lacquer based product. At 30 minutes, I'd rather suspect it's still outgassing, which may be detrimental to an acrylic color/top coat.

As an autobody/paint tech I agree.  While you can top coat fairly quickly, paint will take at least a day or so to fully cure even though it is dry to the touch.  Enamels even more so than laquers or acrylics.

I'd give acrylics at least a full day and laquers 2 days

I can't comment about curing times, as I build so slow my club nickname is glacier!

I have noted in my own use of a dozen types of paint, some are considerably more sensitive to handling.

In my use (your milage may vary) Hataka def. needs a good primer (badger Stynylres or Halfords rattle-can),  with Tamiya & MIG being the most durable to handling.

All paints need time to cure fully, so if, as above, the coats closest to the plastic aren't cured, they can delaminate, with Valejo Polyurethane primers being the worst (imho) for this.

Flory says allow 24 hours for Acrylic, & a week(!) for Enamels.

Have you considered Flory Models Clay based washes, these are totaly inert and don't react to anything.

Here he applies over a unspecified satin finish, but I'm having the least issues (I can't gloss for toffee) with Windsor & Newton Galleria Gloss & Satin acrylic varnish.

Flory Models Tutorial: http://promodeller.com/weathering-wash/

US Stockist: https://www.highaltitudehobbies.com/flory-models-products

Jakealoo

Thanks Stikpusher and Phil_H ... I will increase the drying times as you suggest. Some of the paint manufacturers imply that the first coat can be applied just minutes after using their primer but perhaps that's just a means of increasing sales. I recently picked up a bottle of Stynylrez "Easy App Surface Primer" and it says "Let dry 5 to 8 minutes (3 minutes if dried with an artifical heat source)". Nevertheless I will follow your advice.

 

Those are mighty fast times on that Stynylrez, not to mention weather conditions, humidity factors etc.. I cook it for 30-40 minutes in the dehydrator this time of year, maybe 20 minutes in dry winter weather or let it go a few hours if air drying. And overnight air drying in humid weather. After you work with it for a while you get a feel for it.

Edit: I just shot some Stynylrez this afternoon, thinned a little with 91% ipa. You don't get any more humid day than today around these parts, the primer was still wet after about 8 minutes air drying or so and it's now about finishing up in the dehydrator. There is no way you were putting anything over that primer today without the heat setting. I think it will be dry when it comes out of the dehydrator by looking in there though.  30 minutes @ 105 f and about 8 minutes dry time before it went in.

For a pin wash I always try very hard to keep the wash tight into the line I am applying it to, to minimize any cleanup. I find it is very hard to apply a solvent wash and clean up afterwards without affecting the sheen, even if the color does not come off.

After taking all the advice on board I decided to do a small test on the topside of the Spitfire which I had covered in one light coat of X-22 clear gloss about two weeks ago. The pin wash flowed much better than on the underside (topped with two coats of Klear) although I'm finding that some of the panel lines in this 1/72 kit are so shallow there is very little to flow into.

After letting the pin wash dry for 5 to 10 minutes I was able to remove the excess using mineral spirits without affecting the underlying layers. The only sections that didn't work out as well were those shallow panel lines where removing the excess in some cases removed the panel line as well. Overall I'm pleased with the result and have learned a lot in the process.

Jakealoo

After taking all the advice on board I decided to do a small test on the topside of the Spitfire which I had covered in one light coat of X-22 clear gloss about two weeks ago. The pin wash flowed much better than on the underside (topped with two coats of Klear) although I'm finding that some of the panel lines in this 1/72 kit are so shallow there is very little to flow into.

After letting the pin wash dry for 5 to 10 minutes I was able to remove the excess using mineral spirits without affecting the underlying layers. The only sections that didn't work out as well were those shallow panel lines where removing the excess in some cases removed the panel line as well. Overall I'm pleased with the result and have learned a lot in the process.

 

Yep. Now experiment with length of time the pin wash dries for and the level your wiping cloth/cotton bud/qtip is saturated with the mineral spirits. You can probably let the spirits half dry out before you wipe. Something to play around with at least.

Jon_a_its

I can't comment about curing times, as I build so slow my club nickname is glacier!

I have noted in my own use of a dozen types of paint, some are considerably more sensitive to handling.

In my use (your milage may vary) Hataka def. needs a good primer (badger Stynylres or Halfords rattle-can),  with Tamiya & MIG being the most durable to handling.

All paints need time to cure fully, so if, as above, the coats closest to the plastic aren't cured, they can delaminate, with Valejo Polyurethane primers being the worst (imho) for this.

Flory says allow 24 hours for Acrylic, & a week(!) for Enamels.

Have you considered Flory Models Clay based washes, these are totaly inert and don't react to anything.

Here he applies over a unspecified satin finish, but I'm having the least issues (I can't gloss for toffee) with Windsor & Newton Galleria Gloss & Satin acrylic varnish.

Flory Models Tutorial: http://promodeller.com/weathering-wash/

US Stockist: https://www.highaltitudehobbies.com/flory-models-products

 

 

 

 

 

I've watched a few Flory Models videos on YouTube but I haven't checked out their weathering wash. Thanks for the suggestion.