Why did this happen?

[spitfire]

I did a casting for small project that wasn't a pen and ran into an issue. As you can see in the picture I poured the bottom red layer then waited until it became tacky and gelled then placed the picture on top of it.

The picture I printed onto photo paper on an inkjet printer then put a layer of modge podge on the front and back of the picture.

I then poured the clear resin on top while the bottom layer was still tacky to make sure the 2 layers would adhere. Everything was fine until resin was at the peak of curing(a few minutes after I poured it) it created an air bubble as you can see in the pictures. I don't know why this happened and wanted to see what I should do to not allow it to happen.

Also, the clear resin I had sitting in a cup of warm water to thin the resin a bit to eliminate air bubbles. Could it be that I used too much catalyst making it get to hot?

I put a small screw driver into the pocket and twisted a little and this is what happened.

 

[toolcrazy]

If you didn't let the print dry completely. This might of been the issue or the paper wasn't completely dry. Moisture will do funny things to PR.

 

[spitfire]

I printed the picture one day. Waited 24 hours and put the modge podge on then waited another 24 hours before casting so it should have been dry.

 

[soligen]

This is at the edge of my knowlege/skill, but in an older thread someone mentioned using CA over the mod podge before casting. I think they gave the CA a 2 day cure for out gassing before casting

 

[PTownSubbie]

Modge Podge is the problem if I were to guess. If not completely dried, it will prohibit curing of the resin because it is water based.....CA is a better choice of bonding agent, IMO.

 

[spitfire]

I wasn't using modge podge as a bonding agent but rather to seal the ink onto the photo paper.

I use nothing to glue the paper to the resin because I place the paper onto the resin while it is still tacky thus gluing it down.

Also, I made one before and had the same problem just the air pocket was not nearly as big and for that one I didn't use modge podge.

Modge Podge is the problem if I were to guess. If not completely dried, it will prohibit curing of the resin because it is water based.....CA is a better choice of bonding agent, IMO.

 

[glycerine]

I would say that you are trapping air when you place the picture on the red layer. Next time, take your stir stick or something and spread some clear resin on the back of the picture. Then put it in place and pour the rest of the resin over it...

 

[Padre]

A couple of thoughts:

That would be a LOT of trapped air. Could air be creeping in from an unsealed portion?

Have your tried using a pressure pot? Or how about setting on a vibrating surface while curing, such as a drill press that is running?

Just some thoughts.

 

[jttheclockman]

I would say that you are trapping air when you place the picture on the red layer. Next time, take your stir stick or something and spread some clear resin on the back of the picture. Then put it in place and pour the rest of the resin over it...

I think part of the answer is here in this statement. When placing the paper on top of the red resin there may have been air buubbles underneath and it escaped when adding the weight of the next layer. Whenever you pour try to deflect the pour so that you are not creating air bubbles. Whenever you heat your resin 2 things happen. One is it thins the resin out which is great for less bubbles but 2 the resin sets up very quickly and the more catalyst used the faster it goes. I am talking minutes to get to gel form so if there is air trapped it does not have time to get to the surface. before it is skimmed over. That is my 2¢

 

[spitfire]

I think you may be right because it does setup very fast. So what I am going to try is.

Brush a little resin on the back side of the paper then lay that down. I will also use less catalyst and see what happens. Hope I can get this worked out.

I would say that you are trapping air when you place the picture on the red layer. Next time, take your stir stick or something and spread some clear resin on the back of the picture. Then put it in place and pour the rest of the resin over it...

I think part of the answer is here in this statement. When placing the paper on top of the red resin there may have been air buubbles underneath and it escaped when adding the weight of the next layer. Whenever you pour try to deflect the pour so that you are not creating air bubbles. Whenever you heat your resin 2 things happen. One is it thins the resin out which is great for less bubbles but 2 the resin sets up very quickly and the more catalyst used the faster it goes. I am talking minutes to get to gel form so if there is air trapped it does not have time to get to the surface. before it is skimmed over. That is my 2¢

 

[PTownSubbie]

I wasn't using modge podge as a bonding agent but rather to seal the ink onto the photo paper.

I use nothing to glue the paper to the resin because I place the paper onto the resin while it is still tacky thus gluing it down.

Also, I made one before and had the same problem just the air pocket was not nearly as big and for that one I didn't use modge podge.

Modge Podge is the problem if I were to guess. If not completely dried, it will prohibit curing of the resin because it is water based.....CA is a better choice of bonding agent, IMO.

Either way. I think the modge podge caused it due to not being fully dried. I think Bruce allows his to dry for a couple days if I recall correctly. Bruce, correct me if I am wrong please.

I am not saying modge podge is bad by any means. You just can't rush it. I seal my photos with standard laquer spray from a can. Works great and dries fast. You might want to give that a try.

 

[spitfire]

OK I thought I had read that modge was good to go after 24 hours. So I could use Deft to spray my paper as well? I have no problems waiting if that's what it is.

 

[DozerMite]

Start by using a clear coat spray (any brand you choose) to seal the print.
Use CA (I prefer thick for this method) to adhere the print to the piece. Use a paint stick or similar and start at one edge and run it across the print. Do this twice, perpendicular to each other. This should force out the air. Wait a couple days and do the next pour.

Has worked for me every time, your MMV though.

 

[spitfire]

The second layer will adhere ok to the first layer after that layer is fully cured? I thought for some reason I would have adhesion problems pouring the second layer after the first cured.


Thanks to all for the input, helps greatly

Start by using a clear coat spray (any brand you choose) to seal the print.
Use CA (I prefer thick for this method) to adhere the print to the piece. Use a paint stick or similar and start at one edge and run it across the print. Do this twice, perpendicular to each other. This should force out the air. Wait a couple days and do the next pour.

Has worked for me every time, your MMV though.

 

[DozerMite]

It will adhere fine. I've cast blanks, turned them under size, applied prints and recast before final turning and finishing.

 

[gketell]

That is the beauty of PR, it self adheres. That is one of the reasons it stays "sticky" when you cast it. When we used to make surf boards the only resin that didn't self adhere was the "final coat resin" that actually had wax in it and the wax would float to the top as it cured. And what a PITA it was if you used that then decided you needed another coat.

 

[spitfire]

How long are you letting the clear dry on the picture before casting it?

 

[Thumbs]

Jason,
I have a color laser printer if you think the ink is having any effect. Or if you just want to see if there is any difference between ink and toner. Might be a good check anyway as I've never seen anybody comment on the differences between ink and toner in casting processes. I don't know that there is any difference though.........? Just a thought.
Bob

 

[its_virgil]

I have stopped using Modge Podge for several reasons. Ca is a better choice but sealing the ink is not necessary. I do not seal the ink when I make blanks with computer labels. I suspect air was trapped under the label and escaped when the curing started. But that is just an educated guess since I have not done any casting similar to what you attempted.
Do a good turn daily!
Don

Modge Podge is the problem if I were to guess. If not completely dried, it will prohibit curing of the resin because it is water based.....CA is a better choice of bonding agent, IMO.

 

[Texasbeachbum]

Go to Walmart and get you a can of Krystal Klear spray paint and spray it before you cast it. Its about the best sealer I have found for decals and inkjet pictures. Drys fast too.

 

[turner.curtis]

Good luck with your project. I have nothing to add although wanted to inquire, is that a Disc Golf Marker you are casting? I was thinking about turning some wooden markers for the group I play with and dipping in plexitone. If you are working on custom poured markers I would be very interested in your outcome.