Saturday, March 26, 2011

Lets talk about using air dry sealer as primers when air dry painting

People often contact me for advice about issues they have had with air dry paints because they are aware that I have tested several types mediums. Even if I am not using the brand they are there are some basic similarities to using all air dry paints.

I was recently asked some questions regarding dolls that had gone sticky after being painted and sealed with one of the newer air dry reborn paint systems on the market that incorporates a final air dry sealer as part of the process. (This was not LDC paint.) The reborner had been told by the company to try priming the pieces with their sealer first and then painting because perhaps some of the releasing agents from the vinyl was seeping through the paints causing them to be sticky. The thought was that if the vinyl is sealed before painting this would prevent the problem (if indeed it is a vinyl problem.) Once the reborner tried this, she found that the air dry paints would not stick as well as they did to bare vinyl. It was at this point I was contacted and asked about a possible solution.

Other than some issues with the Secrist vinyls that occurred last year, I do not know of any currently produced vinyls that are leaching releasing agents. I truly think the issues that some may have with air dry painted babies going sticky are issues of technique and not issues from the vinyl. However, if there is some leaching vinyl still out there, it is true that sealing them will stop this. Secrist recommended sealing them with Genesis Matte Varnish before painting to stop the problem. It is possible that using an air dry prep sealer would work but I personally have not tried this so you will have to test it for yourself. If you do, DO NOT use your final sealer product as a prep sealer. I will explain why in a minute. I recommend using Delta Ceramcoat All Purpose Sealer. It is a sealer designed to prep and seal a surface before painting and does bond well to vinyl and not peel up. It also dries clear and does NOT dry sticky. I once tried Jo Sonjas All Purpose sealer but it is white like glue and even though it dried pretty clear it left a sticky residue when dry which will not work for reborn painting. The Delta Ceramcoat All Purpose sealer will leave a bit of sheen behind but it is the best product I have found on the market to use as a prep sealer.

You can buy it at Hobby Lobby or order it from Hofcraft: http://www.hofcraft.com/delta-ceramcoat ... diums.html

As far as prep sealing vinyl with air dry varnish or sealer used as a final sealer for painting I do not recommend doing this. Air dry top sealers are not meant be used as a primer because part of their final sealing property is to create a barrier shield that protects. This barrier surface will act as a deterrent to your paint sticking to the vinyl when you try to paint over it. The final sealers are designed to make the surface more smooth and less porous and resistant to scratches, fading etc. The surface does not have as much "tooth" for the paint to grab onto. Even though bare vinyl feels smooth it still has a "tooth" property because it is porous and that grabs the paint. In the case of the very slick vinyls where people have had issues with the paints not wanting to stick to them the reason is that they have less "tooth" to them and that is why we prime them to make the paint stick.

When priming a surface to be painted you want to use something that will increase the surface "tooth" not decrease it. This is why Genesis Matte Varnish works so well as a primer. This is also why the Delta Ceramcoat All Purpose Prep Sealer works well. Even though it still leaves the vinyl fairly smooth, you can tell that it does leave the tiniest bit of texture or "tooth" to the surface when comparing it to an unprimed vinyl. Also it bonds very well to the surface and won't peel up which is a concern I have about using thick layers of top sealer as a primer.

The other possibility of why some may be experiencing stickiness after top sealing their paint is that there may not have been enough cure time allowed between the last paint application and the sealant application. I think if there is any moisture left in the paints that needs to aerate during the curing process then sealing them will trap it and the moisture will try to get out through the sealer causing it to break down and become sticky. So be sure to wait at least the minimum time recommended by your painting system between the last paint application and applying the final sealer.

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