When using AK worn effects, how long does one wait on the top coat before scraping/brushing for the effect?
Will the technique not work if the topcoat cures too long?

I have seen Mig using it during a demonstration, and he only waited a minute or so after spraying the paint. He said it is best to do one side of a vehicle at a time, otherwise the paint will be too dry.

I myself used the heavy version with Tamiya acrylics and indeed you cannot wait too long. If you do, you can scratch the paint, but when you apply water with a brush, nothing will chip.

Try on a piece of scrap plastic first, I found out the fluid can make your top coat lighter

HTH

Matthijs

about 45-60 minutes before beginning the chipping,and yes,you don't want it to dry too much

Thanks all for the replies.
Another question.
How much of a difference will the topcoat type make?
I am going to use Vallejo which , to me, has a much faster drying time then Tamiya.

Don't think it matters, I use both Vallejo and Tamiya, and usually start the chipping process about 10 minutes after painting.

I've tried using the AK chipping fluid about a dozen times with varied results. The universal constants that seem to give the best results for me are:

1) Use a clear satin coat as a boundary between your base coat and the over coat. Without one, I've had my undercoat come off and expose the primer when chipping without a clear coat. Don't use a gloss! The chipping fluid needs something to “grab” onto so it doesn't come off in huge flakes, which is what the Heavy Chipping Fluid does by design. For more subtle chipping than that, use a satin...a full flat coat has too much texture and the chipping fluid layer will be difficult to remove, so you'll get no chipping.

2) Personally, I've had horrible experiences with using Vallejo as the top coat. Tamiya works far better for me. Vallejo doesn't seem to grab onto the chipping fluid layer very well and comes off in huge flakes, just like using the Heavy Chipping fluid. Could be the way I've been spraying the Vallejo, but it just doesn't work for me...Tamiya does.

3) Start wetting and chipping within a few minutes of the overcoat being dry to the touch. I've waited 10-15 minutes after spraying the topcoat and haven't been able to get any chipping at all. Now I start wetting and chipping just a minute or two after the paint is dry to the touch. With this time frame, I've gotten the best results.

I've also noticed you need to be careful with how thick you spray the chipping fluid...it's a fine line as far as I can tell between too much and not enough. Too much, and you get huge chunks coming off; spray too thin and nothing or not enough comes off. Also watch how much pressure you apply when wetting and chipping....don't scrape as you can scrape right own to the primer before you know it.

Definitely practice on a scrap model or plastic until you get the hang of using the stuff. I'm not sold on it as of yet, and want to try the old fashioned hairspray method to compare the two. For me, the chipping fluid is unpredictable and hard to get consistent results with. I do need more practice with it though. Lots more practice...

Hope this helps in some way...your mileage may vary.

Last question.
How long do i wait after applying chipping/worn effects fluid before i apply the paint coat ?
Thanks

The short answer based on my experience: almost immediately. The chipping fluid will dry VERY quickly, even of you put it on a little too thick...”quickly”as in just a few minutes.

The longer you wait to apply the topcoat and start chipping, the less chipping you'll get and the harder the topcoat will be to remove. I generally will spray the chipping fluid, clean out my airbrush then thin my topcoat and get that ready to spray. In the time it takes me to do all that, the chipping fluid has dried.

The best way to tell when it is dried is to look at its sheen. It will turn somewhere between satin and flat when dried. When it no longer looks wet like it does when you spray it, spray your topcoat. It should literally be just take a few minutes to dry depending on how thick you spray the fluid.

Again, practice on something you don't care about the fist time you try it. I got overzealous my first time with it and had dismal results. Good luck! :-)

Thanks Bill.
At least my first attempt will be small. And i don't want it to be major of the effect.

So i ended up using the Worn effects on my 234/2 Puma mufflers.
I base coated them with MM burnt iron laquer, then semigloss clear, as Bill stated and my Vallejo topcoat.
I just used a wet brush. It worked nice. I didn't go too crazy.
Just wanted to say thanks again.

Glad to hear you had a success with your first attempt!