help!!- washing

There are a few possibilities:
1.) Dirt, oil, mold residue left on the parts, i.e. either insuficient washing or excesive handling(finger oil residue) prior to painting.
2.) Your wash is of the same colour type as the grey you put on, i.e. the solvent from your wash dissolves the grey coat.(most likely from what I read in your post)
3.) Grey coat and wash are incompatible.

I always use waterbased colours or inks for washes and stains as those got the least compatibility problems or lay down a clear coat prior to applying a wash.

I assume you used black acrylic with acrylic thinner as a wash, right? I believe the thinner "activated" the gray acrylic and took it off. The gray paint may not have fully dried yet, or the thinner is just strong enough to activate acrylics even if dried (what did you use?). I would suggest that you repaint the engine block with the acrylic gray. You may have to strip all the paint off first if the thinner made a mess of your previous paint job (you can use Windex or a similar product for stripping acrylics). Then you can do one of two things after the gray paint has thoroughly dried (24-48 hours):

a. Brush or spray on an enamel- or oil-based clear coat and let it dry. The sheen of your clear coat will depend on how the engine block should look like, i.e., if it's shiny or dull. THEN you apply your acrylic wash. Now this shouldn't affect your gray paint anymore as the enamel clear coat is protecting it from your wash.

OR,

b. Instead of using an acrylic wash, use an oil-based wash such as black enamel plus lots of enamel thinner. Since the acrylic is water-based while the enamel wash is oil-based, they both won't affect each other.

Of course, there is a third option which is letting the gray acrylic dry for about a week or so before applying your acrylic wash to make sure the base coat is thoroughly dry (try on an inconspicuous part first), but you may not stand waiting that long. If you've noticed, the two techniques I cited above rely on the principle of two dissimilar paint/chemical types not affecting or reacting with each other. Just keep this in mind and your wash jobs will surely come out well, if not perfect. Hope this helps.

Cheers,
onyan

on onyan and museum, thanks for your comment.
that's what I thought, I use the same type of paint for both washing and painting. that's why the solvent took the gray off.
If I spray them with future or clear coat, will this protect the gray ? but again, it's an engine block, i don't want the to be shiny...

to musem point no3. what do you mean ? gray can't be washed ?

QUOTE: Originally posted by butek If I spray them with future or clear coat, will this protect the gray ? but again, it's an engine block, i don't want the to be shiny...

Clear coat should help as long as it is of a different solvent type to your vray coat.

QUOTE: to musem point no3. what do you mean ? gray can't be washed ?

Some paints can be safely sprayed/painted on top of others, while others will give you headaches.
Get a compatibility chart for different paint types, most good modeling books should have it in.

You can alos try (as Model Museum alluded to) using artists watercolors for a wash. These are sold in tubes. Mix with water and a drop or two of dishwashing liquid. The water will not lift any commonly used modeling paint. Check out Swanny's site for more details.

www.swannysmodels.com

Go to the "Tips" page.

HTH.

-Dan

make future flat by adding a small amout of flat base from either tamiya or gunze. not that you should add flat base, not flat clear.

futuring the engine block ought to do the trick, have you considered drybrushing ?

QUOTE: Originally posted by reggiethedorf make future flat by adding a small amout of flat base from either tamiya or gunze. not that you should add flat base, not flat clear. futuring the engine block ought to do the trick, have you considered drybrushing ?

flat base = primer?
drybrushing, not very good at it. but parctice makes perfect, yes ?
any reference site for this technique ?

I've said it before, I'll say it again. First rule is don't lay your wash over the entire model. Place small amounts where you want the shadow/panel line to show up.
Never scrub or brush a wash on, aply small amounts at a time and let capillary actio do its thing.
Don't use acrylics for a wash, their pigments are just too big; for best results, use artist oils.