Acrylic Question - Engraving Etc. Forum

From:	Harvey only (HARVEY-ONLY)	11 Feb 2005
To:	gt350ed	8 of 10

798.8 In reply to 798.5

I am not sure how old the reply of mine was that you saw. I have switched to tilting the piece backwards and applying a small puddle then rocking into place. It may not always be bubble free but is a great improvement.

The perfection way is to place a sponge in a container and lay toothpicks over it and saturate with solvent. Hold the bottom of the piece on it for about 30 seconds and then rock it into place. That uses an enormous amount of solvent due to evaporation.

This thread has reminded me to do an experiment that I forgot about. I have used PVC pipe joint compound, both thick and thin formulations for badge back welding in an emergency, and it worked well. I need to try it on awards and see it it works better. I usually have scrap around from making awards.[Since my laser I have gone to multi-layer snap on bases a lot, no solvent.]

Philadelphia, PA (Really Bensalem)

Harvey's Sub Page When you finally understand it completely... it changes.

From:	Rodney Gold (RODNEY_GOLD)	11 Feb 2005
To:	logojohn	10 of 10

798.10 In reply to 798.9
If you use tensol 30 or the like , you can flood the flat piece with solvent and just place the other piece atop it , the exposed areas flash off on and only at the acrylic to acrylic contact point will any melt occer. This is a very poor way to bond stuff as the bond strength is very weak. You should chamfer the edge and use a fill type glue to fill in the "wedge". the problem , as I explained is not air bubbles per se , it is the edge finish whose microgrooves can not be filled with a material that has the same refractive index thus making the bond invisible , any high points on the edge will give a really bad bond and dips or low points wont bond at all if you use high flash point solvents. Its better to disolve a small amount of acrylic in the solvent and use this as it slows evaporation and acts as a fill as well as giving the glue a slight increase in viscosity.When we bond stuff this way we fill a syringe and needle with the solvent and run it along the seam between the piece and the flat surface whilst pressing the piece down and capilliary action fills the join. When glueing larger areas to others , it's best to apply glue to the underside of the top piece in a X fashion with a bit of an extra blob in the middle of the X . As you press down air flows out the top and sides of the X and you get a bubble free join, You can laminte large surfaces together with an almost optically clear join this way , the key is the air escape path.