View Single Post
  #5  
Old 07-13-2008, 12:28 PM
Gene Tru Gene Tru is offline
Gold
 
Join Date: Mar 2008
Location: New Mexico
Posts: 123
Default Re: Gene's contest submission

Today I started my design transfer. I've had trouble with a some methods, I think mainly because I do not own a laser printer. I will eventually get a laser printer and some transfer solution. In the meantime, I've decided to use a method I haven't seen or heard of used here on the forum.

Occasionally I do glass award etching, or as is referred to most commonly, 'sandcarving'. It is nothing more than sandblasting an image or lettering onto glass by use of a stencil. Since some people may not be familiar with this process, I will explain some of the highlights involved.

I started my process by determining what size to make the design. Here I just printed the design in different sizes, quickly cut some of them out and laid them on the buckle to decide which size looked and fit the best, keeping in mind that I need the center diagonal space left open for the center panel.






After I decide which one works best, I print the reversed image on a sheet of transparency film. This only has to be done once since I will be using the same design on the top as on the bottom. This particular printed piece was not reversed, I use it to more clearly check positioning.






I temporarily tape the film to more clearly see position and relationships.






At this point I've placed the print on the transparency in contact with a piece of photo emulsion film (or photo resist) (blue) and exposed them under a ultraviolet light for 30 seconds. What that does is harden and set the emulsion except where the UV light is blocked by the black lines in the design. This step is not illustrated here, but is preformed under UV light.

The blue emulsion strip has a shiny and a dull side. After exposing to UV, the strip is held onto this white metal backer dull side up with 2 srip magnets in preparation for washing out of the uncured emulsion thus exposing the design.






In the sink, I wash out the emulsion with a warm water spray for about 3-4 minutes. Only the uncured emulsion washes out thus creating the stencil. The shiny opposite side is what holds all this together. It is not water soluble and when the design is placed on the metal this shiny carrier will be removed.






The blue emulsion strip (stencil) is laid to dry on a paper towel, again dull side up. The dull side at this stage is very soft and tacky. Now you can see that image is reversed, when it dries I will flip it over and lay it on the metal in it's proper position.






While the stencil dries, a milky adhesive is applied to the buckle. It is fast drying and will be totally dry in about 5 minutes sitting in front of a fan. It dries clear.






At this point I place the stencil dull side down onto the buckle. Both surfaces are very tacky so I'm being careful that it is in it's proper position. If lightly placed, I still can remove and reposition if needed before pressing into good contact. Shiny carrier backing is removed at this stage and stencil is pressed down firmly for a good adhesion.






All exposed metal must be covered to prevent sandblasting what shouldn't be.






Buckle is sandblasted or very lightly air abraided (this step not illustrated here). A handheld air eraser will work fine for this step also. I used aluminum oxide but I'm sure glass beads would work also. The surface is very lightly etched, so light in fact that If I make an error at this point a light sanding would clean the surface to start over. After sandblasting, the entire piece is placed under warm running water to soften and loosen the stencil which is then simply rubbed off with my thumb.

In the second photo below, I rubbed black oil paint into the etched design so that it would show up in the photo better. The beauty of this technique is that the design is there to stay. It cannot be accidentally rubbed off.

Every tecnique has it's pluses or minuses, this one does too. Initially may be a little more time consuming, but gets faster the more you do it and the results are great.






Now I can engrave this half of the buckle or I can transfer the other half next. I've got that choice since the first transfer is there to stay until engraved.

I will proceed to engraving in my next posting whether or not I decide to transfer the other half. Procedure will be the same for the upper half as the lower.