Posted by Catharine C. Kennedy on November 12, 2003
D. BernhardtI'm having all SORTS of problems trying to make reverse painted mirrors using the Krylon mirror-finish spray. It puckers up the one-shot paint. Coating the backs of the letters with shellac didn't work (blotches & runs)and using a mask... the mirror finish & spray sealer pulled off with the masking. Obviously I've missed something here! How should this be done (using anything!)? Thanks
Mark YearwoodHave never tried this particular product before although I'm willing to bet that if application allows for it, a "dry" coat first will allow for heavier applications...now this is just a guess but by dry coat I mean just a few very light passes with the Krylon before the heavy applications. Mike put it perfectly when he described how "hot" krylon can get. BTW Goldie...what is happening on this site is truley quite amazing. I try and read a post or 2 and have become lost in all the great stuff here. Am absolutley on the floor right now with all the Rawson and Evans stuff here. The "Boss" would have been so amused and enthralled!
Catherine,
You might do a test piece and when painting add a few drops of a urethane hardener to the 1-shot.
The kind that is used in automotive clearcoats.
This will catalize the enamel and make it more resistant to lifting. I harden all my 1-shot when striping and when it will be clearcoated. I have been clearing over 1-shot for years with great success.
I have also airbrushed urethanes onto the back of etched mirrors. These type paints are less affected by hotter solvents. Enamels need to dry longer, too before anything is applied over them.
Mike Jackson
Catherine,
This is a very new product. Seems like Larry White let us know about it and at the time he had just sprayed a few piece of glass to see how it looked on glass. That's easy...no lettering. I don't know anyone that has EVER used it on a sign yet unless Larry took it a step farther, so you will not get much response here from "the big kids". I think their earlier suggestion of using shellac was simply something they would try first if they were trying to solve the problem. The problem seems to be the Krylon is too HOT to apply over sign lettering enamel. In that case, I would probably consider any option of masking off all future colorized areas with gerbermask first, paint the silver, and then remove the mask and fill in the colors.
This is basically R&D time. You may just have to play around with a bunch of scrap glass and see if you can run across something that works, and if that fails and you get no obvious suggestions for obvious solutions, you might find the product unuseable for reverse glass signs. In that case, actual silver mirroring might be the fall back solution?
I'm sure that if someone here KNEW the answer, they would tell you. It is much too new of a product to have much support.
Good luck! If you find a solution, please let the rest of us know. Personlly, I'd silver it.
Mike Jackson
Mike Jackson - Back to shellac
You commented that shellac didn't seem to be an option because it runs and was blotchy.
Just a couple of comments on that...
You can buy spray cans of CLEAR Bulls Eye Shellac at any lumber yard or paint store. It does spray on relatively clear, in my experience. I don't know if it will yellow slightly over time, but it might. In some cases it might be a plus if it did to give the sign an antiqued patina. Since this is in a spray can, you should be able to appply numerous light spray coats within a 30 minute period, and none of them should run or sag or blotch if you are at all careful, even vertical. If you can lay the glass flat, I can't imagine having any problem at all with those pontential flaws. Once you have a good, dry barrier coat of shellac (an Alcohol based product), it seems to me you should have no lifting of the original under paint caused by the hot Krylon paint.
Again, these are just my thoughts. I haven't tried it with Krylon paint over hand lettering.
Good luck,
Mike Jackson
Denver Chapter of the Letterheads