Full Version: Doming LaserMax
From: Ken D. (KDEVORY) [#1]
1 Jul 2005
To: ALL
The other month I did some testing, epoxy doming on laserMax. (Both the rigid and the flexible UV epoxy.) Everything seemed to work, with the restriction of not using the rigid epoxy on larger items; it could pop off when flexed.
Last week I made a couple of items for a customer. LaserMax, black with white cap; Cleaned with denatured alcohol; UV flexible epoxy; 20 min UV light exposure. They were not delivered yet; yesterday I noticed the epoxy was coming up along the edge in one spot. If I pull on the epoxy it will continue to come up. If I rub the tip of my finger on the underside of the epoxy, where I pulled up the edge, I get what appears to be an extremely thin coat of epoxy the is not fully cured. Almost more of a texture than a layer. If I rub my finger on the LaserMax there it gets a slightly white-ish tint.
As I look at it now, I see areas, in the center, where the photo doesn't look right. It's what I think it might look like if the epoxy was delaminating.
I need to determine if the problem came from the:
* Laser Max
* alcohol cleaning
* Epoxy
* Epoxy application
* Epoxy curing
Does any one have any experience they can share? Doming LaserMax or similar results with other materials? I'm wondering if something I did caused the UV stabilizers in the LaserMax to leach. A process variable would explain intermittent failures.
From: Stunt Engraver (DGL) [#2]
1 Jul 2005
To: Ken D. (KDEVORY) [#1] 1 Jul 2005
Ken,
As you say, there are some variables to consider, but to me, it sounds as if the epoxy never completely cured.
What size was the engraved plate?
From: Ken D. (KDEVORY) [#3]
1 Jul 2005
To: Stunt Engraver (DGL) [#2] 1 Jul 2005
It's oval about 2" x 2.5". I did two at the same time, still no indication of problems with the other.
I don't know if it has an effect, but it's been humid here. I don't know if humidity or temperature would effect it.
I agree with you; I'm leaning toward a curing issue, but I don't think it's about 'UV cure time'. I think something is contaminating the junction. Or is it consistent with cure time issues you've seen?
From: Stunt Engraver (DGL) [#4]
1 Jul 2005
To: Ken D. (KDEVORY) [#3] 1 Jul 2005
Ken,
I had a similar occurence with metal plates. In my case, the semi-cured pieces were at the outside reaches of the viable curing area. The plates in the center were fine.
I'm also finding the flexible epoxy takes about 5 min. longer to cure than the rigid.
From: Ken D. (KDEVORY) [#5]
1 Jul 2005
To: Stunt Engraver (DGL) [#4] 1 Jul 2005
I normally set my timer for 15 min, then take it out when I get to it. Those were 15-20 min. I've had some in for an hour. Maybe I should do 25-30 min.
I did not try the rigid epoxy at this size (2"x2.5"), do you think the LaserMax (1/16" thick) would flex popping it? I know it works with 1"x1.5" but not 2.5"x3"
From: sroehlk (ELECTECH1) [#6]
1 Jul 2005
To: Ken D. (KDEVORY) [#1] 1 Jul 2005
I am not sure why but some materials seem to keep the epoxy from curing. It must react with the material in some way.
I have several types of adhesive backed material that does the same type of thing. The epoxy never cures next to the material.
I use UV cure epoxy and have tried over an hour to cure.
I experimented on a bunch of "waterproof" type papers with adhesive backs. Most do not work because they either absorb part of the epoxy and or dont cure right.
Steve
From: Ken D. (KDEVORY) [#7]
1 Jul 2005
To: sroehlk (ELECTECH1) [#6] 1 Jul 2005
Steve,
I've experienced that too. Its the UV stabilizer added to the paper. It leaches into the epoxy and "blocks" the UV light. Along those lines, I need to "dry" the printouts from my inkjet printer prior to doming. Again it's the UV stabilizer in the inks.
The current situation seems more hit or miss; unlike some papers, I suspect it's more process oriented. I know LaserMax is UV stable. I'm not fully sure if the alcohol I use to wipe it clean after lasering is leaching some of the UV stabilizer.
This reminds me, I need to order more polyester adhesive paper...
From: Stunt Engraver (DGL) [#8]
1 Jul 2005
To: Ken D. (KDEVORY) [#5] 2 Jul 2005
Ken,
Rigid epoxy will flex to some extent. The epoxy shouldn't break away from the substrate, unless a secure bond was never there from the start.
From: Ken D. (KDEVORY) [#9]
2 Jul 2005
To: Stunt Engraver (DGL) [#8] 2 Jul 2005
The overkill approach with the UV light seems to work. At some point I'll need to better determine the actual time needed.
With the flexible epoxy if I really pick at it I can get an edge to start coming up; once it starts it's easy to peel off. That said, given the deliberate effort required, I don't consider it a problem. Is this consistent with your experience?
From: Stunt Engraver (DGL) [#10]
2 Jul 2005
To: Ken D. (KDEVORY) [#9] 2 Jul 2005
Yes, in my experience, once a good adhesion's been established, it takes a deliberate effort to separate the epoxy from the substrate.
From: Ozzy Fox (CLIVEGARAWAY) [#11]
3 Jul 2006
To: ALL
Try laminating the paper, then cutout the badges, and dome them, it does not leech into the paper that way.
cheers