Logo Printing....

[David Schwab]

Right on is a nice cover and epoxy best way to go David. Been fartarseing about with polyester and polyurethane resins for Knobs and switch tops for 15years till I found Epoxy is the only one that comes out of the mold not tacky.

I took apart a broken Lawrence pickup I got back in the 80's that was encapsulated in clear polyester (it was in a closed cover like an EMG), and that sucker was still tacky in some spots... and boy did it smell!

I hate polyester.

[Joe Gwinn]

I took apart a broken Lawrence pickup I got back in the 80's that was encapsulated in clear polyester (it was in a closed cover like an EMG), and that sucker was still tacky in some spots... and boy did it smell!

Sounds like a bad mix. It takes a lot of mixing to get something that viscous to be uniform.

[jonson]

Trouble is Joe the more you mix the more you stir in air and oxygen prevents the cure. So you now have to stick it in a vacume chamber then cure it in a pressure pot which is a whole lot of probs one does not need. Stick to the epoxy and you will have loads less trouble if you get your rubber right etc.

[Joe Gwinn]

Trouble is Joe the more you mix the more you stir in air and oxygen prevents the cure. So you now have to stick it in a vacuum chamber then cure it in a pressure pot which is a whole lot of probs one does not need. Stick to the epoxy and you will have loads less trouble if you get your rubber right etc.

Umm, I don't think that air affects the cure of catalyzed polyester. It's a different chemistry than cyanacrolates.

People also degas epoxy using vacuum, but in both cases the reason is to get rid of bubbles.

[jonson]

Got to differ a bit there Joe. Waxed polyester as in thick skinned guiter finish
is fine and the wax is there to isolate from atmosphere and same with fibreglass polyester resin but Gelcoat they leave the wax out so that the resin against the mold dries but the outer stays tacky to bond the next layers to. Iv'e had some real fun with clearcast polyester ending up having to 2pack lacquer to promote a cure after. Got to the stage of spraying liquid nitrogen into a sealed box containing the mold so being heavier than air it blanketed the surface and stopped the tack. Flaming stuff has it's uses but can be more trouble than it's worth. The stuff also shrinks away from the mold so you can end up with a tack all round it. Some of the new polyurethene casting resins are good even down to promoting a cure down to 1mm thick but boy does that need degassing and really hurts the old wallet.

[Joe Gwinn]

Got to differ a bit there Joe. Waxed polyester as in thick skinned guiter finish is fine and the wax is there to isolate from atmosphere and same with fibreglass polyester resin but Gelcoat they leave the wax out so that the resin against the mold dries but the outer stays tacky to bond the next layers to. Iv'e had some real fun with clearcast polyester ending up having to 2pack lacquer to promote a cure after. Got to the stage of spraying liquid nitrogen into a sealed box containing the mold so being heavier than air it blanketed the surface and stopped the tack. Flaming stuff has it's uses but can be more trouble than it's worth. The stuff also shrinks away from the mold so you can end up with a tack all round it. Some of the new polyurethene casting resins are good even down to promoting a cure down to 1mm thick but boy does that need degassing and really hurts the old wallet.

Hmm. A thin layer of wax is not going to stop oxygen from coming through. Is it the oxygen, or the carbon dioxide and/or water vapor that's the problem?

[jonson]

love debates like this, can be a great learning curve. Yeah that one is correct Joe Water vapour ie high humidity is no help whatsoever but the idea of paraffin wax addative in the poly is it rises to the surface and sits in the top layer as a sealer and the cure occurs underneath. Leave it out unwaxed poly and the cure is very slow or sometimes non existant. Black pigment in polyester is another problem as you allways end up having to double up to 4% on the cobalt accelerator as thecolour seems to suck the life out of it and slows it right down. Sad to say the old Brit health and safety rules now mean a lot of molding poly comes with red paste hardener as used in car body filler which is great if you want to mold in white (pink) they dont want you messing with Mek so you buy it separatly and do your own chemistry which I have ended up at times with a purple smoking high temp mix and pray it's not gonna go bang. Not come across carbon dioxide as a problem and not been mentioned to me by anybody so I'll check that out with my suppliers boffin. Sorry Stan looks like I've hijacked your thread so how are your thoughts on labeling going.

[Stan H]

Sorry Stan looks like I've hijacked your thread so how are your thoughts on labeling going.

That's cool, I'm just enjoying the thread
I may look into screenprinting.

[jonson]

Go for it Stan. Probably one of the cleanest prints you will get and you can use different colours through the one screen. Just make sure you clean it thoroughly every time as I did bugger a screen a few years ago by not doing that and blocked it off totaly. Jig it up and you will get great results.

[David Schwab]

I was watching the Seymore Duncan DVD and he was showing how they get the logo on the bobbins. They were using something called a pad printer and what he called epoxy based ink. I did a search on eBay for "pad printer" and they are pretty pricy. I was wondering if a regular rubber stamp would work with the right ink (since I don't have hundreds at a time to do). Any ideas on what kind of ink would be easy to use and permanent in an application like this? I don't think that I've ever heard of epoxy based inks.

I was just watching the Duncan videos on Premier Guitar, and I forgot in this thread you said it was a Pad printer...

But I looked some up and found this one... $695. Not a bad price.

http://www.screenprintsupply.com/bes...1-SPC-100.html

I hadn't read everything on it yet to see if it handles epoxy ink.

[Sweetfinger]

I actually came into a Kwikprint hot foil stamp machine. Anybody interested? You'd just need to have a die made for your logo/name.

[David Schwab]

I'm interested! I sent you a PM.