Holding down thin brass sheet to a cnc engraving machine

alan2525 · 15-11-2007

I want to cut out some small pieces of brass using a cnc engraver. The parts are small and I'm unable to fix them down using screws and would prefer to be able to fix them down with an adhesive and then apply heat from a small butane torch to melt the glue. The other alternative is to design the parts so they are sill attached to the sheet using small tabs which aren't milled through, but on the smaller Parts I imagine they would still tend tolift and move as they are cut.

I've seen a recommendation to use a product called "gluefilm" this is used as an adhesive for wood veneers.

Has anyone used this stuff with sheet metal and know of a supplier in the UK?

tag · 16-11-2007

Hi alan would ordinary hot melt glue from a hobby glue gun do
I belive there is a low heat version available as well

Regards Tony

bogstandard · 16-11-2007

Hi Alan,
Two ways to consider, I use double sided tape to hold non ferrous on my surface grinder, but the faces should be very clean, either cellulose thinners or meths, not white spirits (use that to get the old tape off or dissolve the tape between two parts), I also use this to hold multi parts together on the miller. The other is carpet stick down spray if sticking it to wood or metal, can be bought from most carpet places, again cleanliness of the surfaces is very important, no loose dust or greases, but does grip like the proverbial to a blanket.

Hope this helps.

John

IainM · 16-11-2007

I have always used cyano adhesives when cutting multiple shapes from thin anything beit brass or ally.
A touch of heat afterwards (like 140 deg - solder temp) breaks the adhesive bond and the parts can be separated. Use the same trick on shims for lathe tools, where each tool is shimmed to the correct centre height. Yeah .. I know all about adjustable tool holders, but try that on an old 36" ctr lathe (circa 1930) - nothing modern fits

Neer mind ... never too old to learn new tricks I say!!
Iain

GeorgePapa · 18-11-2007

Hi Allan,

depending on size of piece I use either the already proposed by Iain CA method or soft solder.

George

alan2525 · 19-11-2007

Thanks for all the tips guys!

I'll try out the CA and Carpet tape and see how it works out.

crash93 · 21-11-2007

This may be what you want. I used the leave tags on route and clamps (picture) and what it was for. I also did som ally window frames with doublesided tape and then used meths (epi) i think its called to remove

Peter

http://www.valeveneers.co.uk/ad.html

alan2525 · 26-11-2007

I had a go with the cyano and had some good results, although on the thinner parts the pieces came free just before the machine made the second pass through the sheet. It was easy enough to clean off the thin sliver of brass remaining but I'd prefer to minimise cleanup time!

I found a supplier for the hot melt laminate adhesive and I'll post some feedback after I've given it a bash.

I'm actually trying to cut some of the iron straps for the side of a 2ft gauge War Dept Goods van. It's 2.5 - 3mm thick so not too much surface area for the adhesive to take hold. I should probably leave - "leave tags" on the items but I'm a bit lazy and would prefer not to have to snip the bits off afterwards. It'll be enough work simulating the 100 odd lag screws in each wagon corner anyhow!

The only problem I can visualise is that the cut brass detail parts look so nice I'm loathed to paint them - so any kind of scale look has gone out the window now!

crash93 · 26-11-2007

Have a look at this stuff its heat activated and can be removed the same way ,, I gave up with peity brass and paint as it looks good when first done but gets tobe a pain polishing it. Peter
http://www.valeveneers.co.uk/ad.html

alan2525 · 26-11-2007

I purchase some of the gluefilm from this place:

http://www.slhardwoods.co.uk/results...ef=departments

I'm just waiting for the delivery as it's taking flippin' ages - isn't that always the case when you want something in a hurry so you can play with it?