Posted by Catharine C. Kennedy- Chatham Center, NY on February 26, 2004
Mike JacksonI've been getting sections that refuse to chip. The glass is evenly frosted. Is there, perhaps, too little glue in the mix? It went on fine and the same consistencey as other places. In reusing glue chips, I mash the pieces down before rehydrating them. For a fix, I've washed the plates off & reapplied glue. Four days on a lamp does seem rather excessive with no action!
Hi Catharine,
In one of the posts below, I commented on not selling a bunch of glue-chipped glass under a short deadline period. You are now seeing one of the reasons for that comment. After waiting four days, you are needing to go at the stubborn areas again. You should be learning a key point at this very minute!
Besides washing off the glue, applying asphaltum around the area and then re-applying the glue, there might be a couple of other suggestions. Danny mentioned getting the glass and room warm and dry, then shocking it by setting it out in the cold for a few minutes. That can work.
Another method is to try using some dessicant to further dry the air around the stubborn areas. To do this, you can cut some 1/2" to 3/4" square pieces of wood and more or less "frame" the stubborn areas. Then pour down a couple of handfulls of dessicant into the area and cover the frame with either plastic sheeting or a piece of clear glass. Seal the whole "tent" with duct tape and let it sit. Within a few hours, it will either work--or not. You can reuse dessicant by drying it a couple of hours under a heat lamp. Most dessicant comes with indicator chunks that turn pink if they are full of moisture, or turn blue when the moisture is removed. You can probably find gallons or half gallons of crystal dessicant at a flower shop or hobby shop. It is often used to dry flowers for flower arrangements, though it has lots of other uses.
Good luck,
Mike Jackson
Bill Blumberg
Danny BaronianCatherine: Here's another possibility for the lack of chipping; sometimes in our eagerness to pour the glue we forget to make sure the glass is completely clean. Perhaps your compressor is super atomizing some oil as you blast and is contaminating your blasted area, that oil becomes as good a resist as asphaltum. I always wash my areas to be chipped with rubbing alcohol, its cheap insurance. Your second attempt will probably work well because you are washing the glass . Good luck, Bill
PatrickCatharine,
Check out this post by Mike on the next page. (http://www.theletterheads.com/wwwboard/ ... /4220.html)
The photo shows how he outlined the letters as a modified version of Pat Mackle's method of chipping.If you paint asphaltum around the areas that have not chipped to prevent glue from spreading, and apply more glue over the frosted areas, it will protect the chipped areas.
Four days seem excessive for chipping but it can take some time. That's why I mentioned putting them outside in your area or for those in a warmer climate pop into the freezer for a few minutes. I do that often and it really shocks the glue, and seems to speed the process up. Just don't overdo it or it will crack more than the glue. I think the biggest factor seems to be the humidity.
I think all of us would like to know how to do a perfect chip every time without frosted areas. Check out the attached photo, all of us still get frosted areas. This is a sample Rick did.
Danny
I have found the two things that stiffel the action of gluechipping are that the glue is either too thin or too thick. Too thin and it will never completely chip if at all, too thick and it will sit there totally under stress to where you can see it tearing at the edges but nothing more. Sometimes it can be triggered to "blow up" with the touch of a Mikita die grinder nicking the surface.
The glue is borderline to being too thin to chip if when held to the light you can see the texture of the sandblasting on the surface of the glue. This is the range where if the glue does chip it will result in a fern pattern.
A deposit of glue slightly thicker than that begins to bring the chips into the range thats most desireable for gilding and silvering, producing the deeper curved and brighter chips that reflect the light so well.
Care should be used in applying the glue so that irregular thicknesses of glue (through drips or areas that join or flow over each other slightly) are avoided as these can prevent chipping or leave a "history" in the pattern if they do chip.
I am still experimenting with several grades of glue and observing the nature of how they work. At one end of the group is the glue I got from Esoteric. It is a light golden carmel color and appears highly refined. Its viscosity is uniformally smooth and has a mild odor, it may also contain a bio agent to discourage mold growth.
At the other end is an old bag of glue from the now retired Peter Cooper Co. This glue is very rough grade and is dark almost burgandy colored. There are traces of hair, wood that floats to the surface, and sand grit (which I think was on the cow hide as residue from the feed lots.) This glue while cooking in the pot fills the shop with a rare odor. (I'm thinking Ogar's breath)
The main thing that I would like to learn is at which point the glue developes the pattern in which it will chip, and what controls that. Its very curious to observe
the various results of the gelatin, it seems have a specific pattern or reason, kind of like Rick's fractiles.
Pat
Denver Chapter of the Letterheads