Advice on 'optical' adhesives please...

[Buriedcode]

Hi peeps,

I've been searching the net for a while now, and I'm probably missing something obvious, but I thought I might as well ask you guys....

What kind of adhesive is 'clear setting'? I'm trying to 'bond' an led into some clear acrylic, in the hope that the adhesive would essentially 'get rid' of the lens of the LED package, to increase viewing angle, and allow all the light from the LED to enter it (reducing fresnel/instertion loss).

I know that there are special acrylic cemets for bonding acrylic together, that sets perfectly clear, and forms a perfect join (after all, the cemet melts, and drys AS acrylic). I was thinking about good 'ol 2-part epoxy resin. But I have limited experience with it, and the only stuff I've worked with dried 'milky'. If anyone knows some easy-to-use stuff, that dries water-clear, and will bond the LED epoxy package to acrylic (or plexiglass) I would be grateful. Preferably so that the LED lens has no effect.

I realise this isn't exactly 'electronic' design, but I'm always impressed with the repsonses in this forum....experienced people are valued

Regards,

BuriedCode.

 

[echo47]

Edmund sells some optical adhesives. Maybe a good starting place.

 

[IanP]

Try to ask at "nails" shop/studio; apparently they use acrylic powder which is then desolved in acetone ..
Other option is to prepare clear acrylic glue by yourself:
get/cut some clear acrylic scraps and leave them in acetone for at least 24h: **broken link removed**

Regards,
IanP

 

[Buriedcode]

echo47, IanP, thanks for your responses.

I checked Edmund Optics/Scientific, the adhesives they have are expensive, and UV cured...but you're right, it was a very good starting place (free advice, and finding what chemicals are used for the process). Thanks man.

As for 'making your own' acrylic cemet. I came across that article myself, its a good idea because I can make up the stuff, as and when I need it. Unfortunatly, I can't find any acetone anywhere I think it was banned here in the UK, because its a strong carcinogenic (causes cancer, and nasty health problems)... I could be wrong.

That said, premade 'decent' cemet is very expensive (I'm basically a cheap-skate). But the 'nails' idea is pretty good. The stuff my sister uses is pretty much 'superglue' (cyanocrylate) which I've tried and it does indeed 'melt' the acrylic, but its not water clear.

Anyway, all this is for some silly little project I've got, which involves making lightguides, and various pretty LED displays for my computer. And my little 'experiments' are simply testing various methods of mouldings, acrylic shapes, TIR, etc..

THanks again, hopefully I'll have a website up soon, with all my idea's....modding for 'engineers', not 'computer people'

BuriedCode.

 

[throwaway18]

Unfortunatly, I can't find any acetone anywhere

You did not look very hard. You can buy pure acetone on ebay uk.

 

[Buriedcode]

I probably could buy it on ebay...but...its acetone (?) Its not the most pleasant stuff in the world and I'd prefer not to use it. I know sometimes chemicals are banned 'just in case'..but I'd really rather not handle it. I'm not equipped to handle powerful solvents, then again, I suppose epoxy resin ain't exactly 'safe'.