My models is on this site called RESTORE ME in scratch build and conversions.
So I sprayed the models in Vallejo Matt Varnish following Robs Scratchmods recommendations in his book. I add one drop of flow improver and some thinner and the matt varnish which had a really good shake it has a ball in the pot as well. It dried Shiny like. silk finish not Gloss though. Thought ok I could live with that , Did the same process with the chipping medium opps !!!! disaster struck it went all tacky and still was three hrs later so thought must be ok. sprayed the model and parts of the model did not dry at all. the spare body had not been painted and still after 6 hrs was very tacky to touch. I decide to wash the model and hope it would come off. So when I put all the model parts in a bowl of washing up liquid and water some of the paint just come off rest I gentle scrubbed off what I could get off. Models are drying Matt and my delicate finish of the wood has not been destroyed Phew! Its now going to dry for 24 hrs.
So what do I do Now once I have repaired the truck etc , do I hand paint chipping on and salt again and do tiny bits at a time? but I want to use multi colours to show its been painted. a few times in real life and has been abandoned.
Hey Ossie, my apologies for not chiming in earlier. With any luck, Rob will pop in as well giving his take since it sounds like you are following his instruction from the book or other postings.
First, with regards to the Matt Varnish. This should dry dead flat. I do think the introduction of the flow improver might have something to do with the sheen. But as you mentioned, this is not something you would normally need to be concerned about at the outset. I often use the Satin to clear coat in between weathering. The semi-gloss coat will allow a little more ease in manipulation of the weathering.
As for the chipping medium....it will dry tacky. This is similar to hairspray and the method therein. Depending on how much you put down and how you applied it, will affect the final results. For standard light chipping I will cut the chipping medium with a little water. Possibly one drop of water for three drops of chipping fluid....but this is a "feel" sort of thing. The more you put on, the more the tacky surface will present itself. Salt will work with the chipping medium, similar to what is seen with the hairspray technique, but there can be some different reactions at the back end depending on the water used to remove the paint and salt. In addition, I did not red what paint you were using with the chipping medium. Was it Vallejo? More curious than anything else at this point.
Basically, If you were going to try again, I would suggest applying a couple of thin coats of chipping medium building up to a desired coverage but not so much as to coat the surface with a thick layer. You should be able to make the multi-layer effects with the medium and salt. I have done this successfully for three or more different colors layered at one time, however, it is easier to paint and chip your first layer, clear coat again once you are happy with the first shot, add chipping medium and repeat the process with the secondary and or more coats as desired.
Hi Thank you for your reply . I am using Vallejo paints at this stage and most of the weathering but do have scale 75 I might use as a matt glaze after I achieved the look I want may do this yet to decide. I will follow the way you describe and let you know . so I am going to try and paint by hand tonight a small part of my test peace in chipping medium with thinner only or water and also try some hair spray , and them spray tomorrow and see what I get.
But what worried me was the paint was also tacky on the model after it had dried . But I will try again . Thank you Ossie
So top right is hairspray very light coat dried with hair drier dried matt paint dried matt
Bottom right Vallejo chipping medium mixed with water and painted on by hand dried same length of time with hair drier , dried matt and no tacky ness,
Bottom left Vallejo Chipping mixed with Thinners in a one drop to three and hand painted on dried same time with hair drier and stayed tacky All painted white by hand
Has you can see they were chipped 10 minutes after wards and bone dry . so unsure what went wrong before but I think I will hand paint the medium on my model or I might go hair spray unsure . no flow improver used and all same bottle of chipping and Vallejo white painted by hand on top
Personally I think you found the culprit...possibly the flow improver. I have found the improver to be okay when shooting large quantities of paint, such as 10 drops or more. You probably could do the same test with an airbrush without the FI and gain the same results. Best of luck on the next round!