REPAIR OF BROKEN VERACRUZ AMETHYST POINT

.i think that can't work well with small specimen who's need great precision to be repaired and how the glue react with time ?she probably change of color too.i change windows and doors for living and often the wood glue in some part of the wood frame was turn yellow when i a change old wood windows for brand new in aluminium.many of the glues i use in my work not really seem to fit for minerals specimens repair.bye

Hello,

Every glue will turn yellow after years.
In the case of your window, they may be turn yellow faster because of the difference of temperature.

A fossils repaired with wood glue will be keep in a confortable temperarature of your cabinet.
Anyway, just because the wood glue is easy to remove with water i keep using that glue and never again the cyano.

If you want i can let you keep in touch with two very knowlegeable fossils preparator in France, they wil tell you exactlly what i explain because they teach me.

No one know for sure what will be the reaction of any glue after 30 or more years!!!!

Bests

Michel

thanks for your answer.bye

All polymers are unstable in permanent contact with oxygen (ambient air) or when exposed to daylight (UV irradiation). In the long run, they will turn yellow which is a sign of partial decomposition (another sign is increased brittleness). To prevent this from happening, manufacturers add stabilizers which slow down the process, but never are able to fully stop it. The additives are either antioxidants (compounds that are more easily oxidized than the compounds they have to protect) or UV absorbers (compounds that absorb UV light with the potential consequence of being decomposed themselves, reducing in this way the UV intensity to which the polymer is exposed). After a certain time, the additives will be consumed and there is nothing left to protect the polymers. Very often though, it is the decomposition products of the stabilizers that are responsible for the yellow colour. Therefore, the polymer does not loose its mechanical properties instantaneously once it turns yellow. The colour will indicate however, that it may be time to replace it.

hi, my only problem using epoxy glue it's than this kind of glue turned yellow with time but if all glues became yellow ,i think i will just continue using epoxy.about fossils repaired with wood glue , i know it's something really often used but i own a mammoth thoot stabilised and repaired with wood glue and i think than this white glue give a unnatural look to my thoot.maybe it's cause this glue are the better way to protect it than they use it but i hope they will find something better someday.bye

Hello Yanick,

How come your mammouth tooth look unnatural to you!!!

Because if the job is done properly it's impossible to see the glue in between the two parts.
I mean if they have correctly used a clamp or more to tight the two piece,

Thanks Peter to your good explanation

Bests to all

Michel

hi Michel .i found a lot of big white glue spot all over the tooth .the guy doing the job seem to only dip the tooth in wood in glue in place to use a simple kind of liquid polish.the tip of the tooth supposed to enter in the jaw was glue back in place with wood glue but this glue out from the crack at many place.sorry i cannot explain it more in english if you want we can continue in one of my old topic in french message board or by pm.bye

If French is better for you, it sounds good..
You can use PM.

If you write before friday ok, or you will have to wait for some days beacause i leave home for vacation..

Michel

I know this is an old topic and I'll probably get spanked for this, but the Herkimer diggers often repair their quartz clusters with Loctite glue made for glass. It has the consistency of wood glue and also has an incredible bond. I repaired an 80 lb. (60#+20# repair!) calcite cluster and felt very comfortable moving it around afterwards. The Herkimer diggers all use Loctite because they said it has the same refractive index as quartz. I know on the quartz repairs I've made that they all came out looking exceptional, even though I haven't used a microscope on them. I have no idea about how it ages in regards to yellowing, but again, it is the industry norm for Herkimers and any signs of yellowing would show up there first. The same for cleanup, as I use Rock's advise on not using too much. I often use painter's tape wrapped around pieces when letting the glue dry, as the tape leaves no residue and is completely flexible and once adhered (to itself) it does not adjust, unlike rubber bands. Loctite makes many formulas for many applications, but the one used for glass is the best one for quartz. For purchasing, it is rather easy and can even be purchased at most Wal-Mart stores. Since I've been introduced to Loctite, I can't even imagine going back to any other type of glue.

Loctite Adhesives
Henkel Corporation
www.loctiteproducts.com
1-800-624-7767

There is no such thing as an "industry norm". There may be rules and guidelines industrial branches have agreed upon, but norms are set up by independent organizations (thanks god !).

The term "industrial norm" was to indicate diggers that commercially produce Herkimer Diamonds, as opposed to ones that recreationaly dig for them. The word norm, is short for normal, which is exactly as it sounds, the normal procedure used by said commercial diggers to repair quartz. I have not met too many commercial diggers up there that use anything other than the normal Loctite adhesive, which is what my comment was about.