what did I do wrong, trying to cast paper??

[ALexG]

Can someone bring some light with my first paper casting?, I had a friend who is a painter and wanted to feature some of her paints on pens, so I did:
1) printed avery labels with an inkjet printer
2) applied the label around tubes and seal the ends with playdoh
3) applied 2 coats of spay lacquer to bring some extra gloss finish
4) glued some exotic wood pieces on the end of each tube to bring some accent
5) prepared about 6 oz of Silmar 41 and warmed it in the microwave for 30 secs to eliminate bubbles
6) mixed 5 drops of mek per oz
7) poured carefully resin into mold , eliminated any visible bubbles
8) put a block on top to avoid tubes to float on the resin
9) placed mold into toaster oven for 1.5 hrs, I always did this and no problem before

at the end I've got a gazzillion of micro bubbles around the labels, which made all this casting totally useless, what could caused them?

 

[PTownSubbie]

Can someone bring some light with my first paper casting?, I had a friend who is a painter and wanted to feature some of her paints on pens, so I did:
1) printed avery labels with an inkjet printer
2) applied the label around tubes and seal the ends with playdoh
3) applied 2 coats of spay lacquer to bring some extra gloss finish
4) glued some exotic wood pieces on the end of each tube to bring some accent
5) prepared about 6 oz of Silmar 41 and warmed it in the microwave for 30 secs to eliminate bubbles
6) mixed 5 drops of mek per oz
7) poured carefully resin into mold , eliminated any visible bubbles
8) put a block on top to avoid tubes to float on the resin
9) placed mold into toaster oven for 1.5 hrs, I always did this and no problem before

at the end I've got a gazzillion of micro bubbles around the labels, which made all this casting totally useless, what could caused them?

Couple things come to mind.....

Rather than using laquer, I would coat with CA. But that is a personal preference.
If you use laquer, let it dry and cure for at least 24 hours to gas off. The bubbles may be a reaction to the laquer curing.
Why did you heat the resin in a microwave? Just use hot water in a bowl and place your cup in the bowl to give the cup a hot water bath. I am not sure what the microwave my have done chemically to the PR.....I just haven't done it or heard of anyone discuss using a microwave before.....

Just my 2 cents.....

 

[PenMan1]

Yep, Fred nailed it. A coating of CA is almost a must with label casting. Additionally, after sealing the label with CA, I let the CA degas at least 2 days, otherwise I get "shiney" spots where the Silmar meets the CA.

 

[seamus7227]

Can someone bring some light with my first paper casting?, I had a friend who is a painter and wanted to feature some of her paints on pens, so I did:
1) printed avery labels with an inkjet printer
2) applied the label around tubes and seal the ends with playdoh
I would use silicone plugs like Fred(PtownSubbie)uses with his silicone molds.
3) applied 2 coats of spay lacquer to bring some extra gloss finish
I would also use CA and let it outgas for at least 24 hrs before pouring resin.
4) glued some exotic wood pieces on the end of each tube to bring some accent
not sure, but some of your air bubble issue could have come from air within the wood unless it was stabilized and then i would still bet it could have been an issue.
5) prepared about 6 oz of Silmar 41 and warmed it in the microwave for 30 secs to eliminate bubbles
As Fred and PenMan1 also mentioned, use a hot water bath ( most of us use the Ultrasonic (heated) cleaner from HF. I use it for at least a cyle and a half
6) mixed 5 drops of mek per oz
my personal preference is 3 drops per ounce
7) poured carefully resin into mold , eliminated any visible bubbles
8) put a block on top to avoid tubes to float on the resin
9) placed mold into toaster oven for 1.5 hrs, I always did this and no problem before
Lastly, this could have the biggest part of your failure on top of everthing else above that i commented on. I would bet that you had some massive shrinkage of resin as well with all of that heat. It has been my experience that you have to control the temperature being applied to the casted pieces. I guess what i mean by that is by not overwhelming the resin too much heat too fast. Your resin will end up being very brittle, shrink faster and potentially crack.

at the end I've got a gazzillion of micro bubbles around the labels, which made all this casting totally useless, what could caused them?

My opinions are above

 

[ALexG]

wow, and I thought that I knew how to cast , thanks for all these tips, I'll try again with one kit only, just one question, does it matter which type of CA you use, I mean thin or medium

 

[PTownSubbie]

wow, and I thought that I knew how to cast , thanks for all these tips, I'll try again with one kit only, just one question, does it matter which type of CA you use, I mean thin or medium

The short answer is No it doesn't. Use the one you are comfortable with but make sure you get a good and complete coverage.

I would recommend you test with something other than expensive painted tubes until you get the procedure down.....

 

[SDB777]

You pour and then put it directly into the toaster oven? Or did I misread that?




I seal stuff with ModPodge, but let it 'rest' at least 24-36hrs before putting PR resin on it.



Scott