A member of 'British Railway Modelling in Australia' (facebook page) accidentally found out why you don't thin Humbrol Clear Gloss Varnish with Windex. Watch the video to find out why... Cheers, Gary.
I could be wrong, wouldn't be the first time!, but to me it sounds like the varnish bloomed, it sometimes happens when the area where you are doing the spraying is a little too cool. As I say I'm probably wrong, but it is worth remembering that paint sprays better at room or a little above temp. Cheer's, Pete.
And here are two more factors that may have affected it:- Humbrol website "Application Shake well before use - some settlement may occur. Apply thinly with a brush or airbrush. To achieve a higher level of the desired finish, apply additional coats. Do not use in temperatures below 15ºC or in conditions of high humidity to avoid the appearance of a cloudy finish once dry."
Ian is a pretty credentialed modeller and lives in Perth, Western Australia. The weather there has been warm throughout the week of the air brushing. He has air brushed and weathered many model previously and this is the first time this has happened. It is also the first time he has mixed both the Humbrol product with Windex. Ian uses Windex for thinning various other acrylic paints and has not suffered the same issues. Cheers, Gary.
On some other forums the use of Windex has been used as a thinner for various paints. However, I have never been one to advocate the use of thinners other than the thinners from the manufacturer of the paint. I have too many things go wrong including ruining a model that I had spent a lot of time building. Sure the manufacturer's thinners may cost a few pennies more but trying to reclaim or salvage a model cost a lot more in time and money. Kind regards Geoff
I’m thinking the windex may have a small water content that will work ok with a colour paint as will slow the flash off of the solvent but with the clear this will result in the cloudy finish as when it’s applied in high humidity With clears I try and stick with the manufacturers own thinner if it’s not the same as other generic thiners Still not sure why using windex instead of specific thinners ??? Trying to save a few $$$ may be but if you find a supplier most products can be purchased in bulk at a very good price eg isopropyl alcohol I get a 5.2L bottle of 100% for the same price of the 70% 500ml bottle at the local hardware then decant and cut as require
Glad you were able to get it back to something like normal. I suppose the lesson for us all here is to try it on a scrap piece first. Tony.