Jump to content

An interesting painting problem


Warden54
 Share

Recommended Posts

So I begin working on my latest WIP last night. After spending probably a grand total of 8 hours on the cloak (and going through one repriming after I fubared the first crack at it) you can imagine my horror when I looked at it again only to see the base coat of the paint was cracking like a busted windshield. Granted the damage wasn't THAT bad, but it frustrated me since some of it cracked near the highlighting I had done, making touching it up particularly difficult. I just wanted to know, has anyone else experienced this problem? What could be the cause of this? I had watered the paint down (about 3water to one paint, just an estimation though) enough to cover the surface area, and I had put two layers(albeit thin) on the cloak. Also, my mini table might not have been in the air stream for the AC to hit it so it could have been higher 80s on up on that painting table. Don't know if that would explain it or not though.

Link to comment
Share on other sites

  • Replies 27
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

I don't recall that being one of the colors that had this issue. It could be the primer, it could be that you didn't shake the primer enough to really get it mixed. Again, I have primed in hot temperatures and not ever experienced this problem and it definitely gets hot and dry in Colorado. I don't recall Imperial Purple as having any issues with it. We might have to wait for Anne to step in and say something.

Link to comment
Share on other sites

  • Reaper User

I've not had problems with the Imperial Purple on this issue. We're working to figure out what the deal is with this effect and it's a relatively recent development (Jubilee had reported it to me first, a while back). It may indeed be a result of not allowing a coat to completely dry before putting the next one on. On the off-chance that this is also a side effect of flatting the paint down to dead matte we will probably take it up to a slight sheen and see where that gets us, although the effect appears to be extremely erratic and hard to pin down. ::(: I've only had this effect happen to me twice, so it's proving hard to gather information to draw any conclusions about cause. But no, Imperial Purple has not been reported as a possible "problem" paint until now.

 

--Anne

Link to comment
Share on other sites

I occasionally experience crackling with the following colors:

 

Mahogany Brown

Walnut Brown

Jungle Moss

Breonne Blue

Woodstain Brown

Dark Elf Shadow

 

I still have not been able to pin down what causes it. I've had it happen with miniatures I primered an hour ago with spray, and with models I've primered a few days ago. I've had it happen with miniatures I have cleaned with soap and water before primering and with miniatures I have not. For a while, I thought maybe my brush cleaner had contaminated the water, but I've had it happen with clean water and brushes that haven't touched soap since the last color I was using with them. The first time it happened, I had recently started using slow-dry, and I thought it might have been that. I removed it from my gunk mix, and still get the crackling occasionally.

 

I have found that it has nothing to do with putting wet paint over wet paint. In fact, sometimes I can salvage the crackle if I immediately paint another layer or two of paint once I notice it. With the most recent experience, put a thin layer of brush-on primer and re-painted and now it's working alright.

 

I can't recall ever having the problem with imperial purple, but it wouldn't surprise me.

 

I would suggest examining your paint very closely before adding highlights. I've never had it happen with any color other than a shadow color I put down as a base coat, which might support the idea that it's something to do with the primer.

 

Do you use Kylon primer?

 

/ali

 

ps. Anne, the walnut brown I have is *very* shiny and I got the crackling with it, so I don't really see how it could be the matte additive.

 

pps. Also, I think Anne once suggested to me that it's a matter of humidity rather than heat that's making the primer cause crackling. OTOH, I've never had the crackling occur with every color on a model - one of the above colors will crackle and the others in other places won't. It does occasionally get humid where I am, so it's a possibility.

Link to comment
Share on other sites

In the housepainting trade its called "alligatoring" and can be caused by putting a harder type of film on top of a softer type of film -- like putting enamel over latex.

 

I would look at what the bottom layer was, and if it is happening with certain colors, check to see if those colors have more additives which contribute to film forming/hardness. The comment that one color was shiny might indicate a different amount of a film-forming ingredient in the mix.

  • Like 1
Link to comment
Share on other sites

  • Reaper User

Ah hah!! PBN, you just might have it...is it possible that the primer is softer than the paint, is my thought...since it's happening with shadow colors, and they use a paint base which is harder than the lighter colors, that could be the cause! It would also be the reason why I generally don't get it, as I almost always use a hard enamel-base primer for my minis...

 

Interesting and thanks for the info, now to test it!

 

--Anne ::):

Link to comment
Share on other sites

Everyone uses some sort of solvent based spray primer anyway, so Reaper might as well make a dip/brush primer which has solvents & chemicals in it. Then you can formulate it properly.

 

I'd like to figure out how to formulate a primer that has cellulose fibers in it so that it would absorb pigment like water color paper.

 

So the darkest color of each triad is formulated to have a harder film? I don't know how much thermal expansion lead or tin figures exhibit, WRT the paint film's glass transition temperature vs % elongation.

Link to comment
Share on other sites

  • Reaper User

The shadow colors are simply formulated with a paint base which has a higher acrylic content, which leads to them drying harder than the medium shade or light colors. This is simply because this was the base available to us which had the characteristic smoothness I was aiming for. We're still attempting to get a dark-color base made that's the same as our light and medium, but unfortunately the paint company we're working with has been very resistant to this. Still, we're working on it! I don't so much mind the greater hardness of the darker colors because it also leads to greater adhesion, so the paint sticks to the models better, but if it makes the crackly issues we'll need to figure out what we can do to fit that. ::):

 

--Anne ::):

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...