More resin troubleshooting

Originally published November 2012.  Updated November 2018.

If you have ever used resin only to get less than desirable results, you’re not alone.  While resin is a fun and versatile way to make jewelry, it can be a fussy beast as well!  These are a few of the most common resin troubleshooting problems and what you can do about them: 

1.  “Stains” or dark areas on embedded items.

 

moisture stains on paper

This is when you embed papers or porous items into your resin castings only to see later that the item has stains or dark areas on it like it is wet.  This happens when the resin soaks into the paper.

Solutions:

Coat any paper or porous items ahead of time with a clear-drying white glue such as Ultra seal glue or an aerosol sealant such as the Castin’ Craft gloss resin sealer spray

These techniques are helpful for how to papers and other items sealed for casting in resin:

 

2.  Resin castings are cloudy or full of bubbles.

This can happen when the resin reacted with the embedded items.  The resin can react with your embedments, especially if you are talking about vintage papers (lots of acid!).

There are a lot of reasons why bubbles can happen in resin.  Here are 10 tips for getting rid of bubbles in resin.

Solutions:

Coat embedments in sealant before using.

Make sure the resin in warm before mixing.  Put both bottles in a warm water bath for 5 to 10 minutes before pouring.  Be sure your containers are dry before working the resin to avoid any water contamination.

Are you trying a new colorant or addition?  The resin may be reacting with that item.  Once again, make sure all additions are dry.

You can watch some of my best suggestions on how to avoid bubbles in resin:

3.  Resin is not fully cured after suggested curing time.

This can be anything from still a bit sticky on top to a big goopy mess.

Solutions:

Follow label directions precisely.  Do not add more or less hardener and measure accurately.  While it is popular in a lot of other blogs and you tube videos, I never suggest using the caps to the resin bottles as measuring tools.  You cannot get an accurate measurement this way.  Use the proper size mixing cups to measure and mix your resin.

Make sure your mixing utensils and containers are dry.  Resin hates water!

Store your resin in a climate controlled environment.  Having resin in an area where there are big temperature swings (such as a garage or storage unit) can allow condensation to form on the inside of your resin container lid.  This moisture then drips into your resin.

Make sure you mix the minimum amount of resin needed for the chemical reaction of curing to occur.  For example, if you’re working with a 1:1 resin to hardener resin kit, you cannot mix two drops of resin to two drops of hardener and expect it to cure.  Resin curing is a chemical reaction that requires a minimum amount of each component for it to occur.  This resin casting article contains a PDF link with the information for the resins sold in the Resin Obsession shop.

Mix thoroughly.  This video shows you how:

If your pieces end up being just a bit tacky on top, you can try sanding them down and recoating with resin.  If your resin is a semi congealed mess, there is not any way to save that resin.  You can try to scoop it out of the mold and clean with home improvement store acetone (wear gloves when doing this!) to remove the leftover resin, but it may be easier for you to toss the mold and start over.

Like this post? You may be interested in  Why is my resin sticky – my resin is sticky - why does that happen?

4.  Resin sticks to my mold.

Assuming your resin is cured, you can try these tricks, otherwise, see number three above.

Solutions:

First and foremost, I always recommend using a mold release — even with silicone molds.  It’s a good habit to get into and prolongs the life of your mold.

If cured resin is stuck to your reusable plastic mold, you can try placing the mold in the freezer for a minute.  Remove the mold and see if you can ‘slap’ or ‘break’ the resin out of the mold.  (You can try smacking the mold on a hard countertop.)  If the resin doesn’t come out, you can try putting the mold in the freezer for another few minutes.  In my experience, if the resin doesn’t come out after 10 total minutes of freezer time, it’s not coming out.

If the cured resin is stuck to your silicone mold, I’m afraid there’s no way to get that out.  However, that brings me to another important point:  polyurethane and silicone don’t play well together.  Personally, I have never had a problem with properly cured epoxy or polyester resin sticking to a silicone mold.  The times I have heard about resin sticking to a silicone mold have always involved silicone and polyurethane where a mold release was not used.  Of course if you’re casting silicone into silicone, you will absolutely need to have a mold release, otherwise you will create one large block of silicone.

5.  Resin gets hot and cures within minutes.

There is always a little bit of heat when resin is mixed due to the exothermic nature of the reaction and curing.  Excess heat, however, will cause the resin to cure very quickly.

 

Solutions:

Use the proper mixing utensils and containers.  While I understand it is tempting to use old plastic bottles, party cups, and styrofoam containers to mix resin, these items have chemicals in the surface that can accelerate the reaction that occurs between the resin and hardener.  Try to use plastic cups designed for resin.

Do not add more hardener than is recommended.  This will speed up the reaction and can cause the resin to cure very quickly.

Do not mix more than the recommended mixing amount of hardener and resin together at once.  This resin casting article contains a PDF link with the information for the resins sold in the Resin Obsession shop along with their minimum and maximum mixing amounts.

What other resin curing problems do you have that you would like advice about?

 

Unpublished Blog Posts of Resin Obsession, LLC © 2018 Resin Obsession, LLC

72 Comments

gizem

Is there someplace to find information on proper care and cleaning procedures of utensils and mixing containers?

Reply
Katherine

@Gizem, Wipe your containers and stir utensils while they are still wet with a paper towel and acetone. (Be sure to wear gloves when doing this.) If they have dried already, try soaking them with a very hot water and Tide laundry detergent.

Reply
Andrea

@Katherine, great tutorial as always!!
I realize this is a tutorial for trouble shooting, but the snoopy is a perfect example of how to salvage a piece you might otherwise throw away…
No need to through out most resin pieces that didn’t quit turn out. With a little creativity you can salvage most pieces.
The scene is a winter/Christmas scene. The seepage is at the bottom & a bit at the top…
Add a bit of fake snow mixed with a tad of white glitter & glue on to the bottom to cover the bottom error. Add glitter or a small bow to the top error. Let all of that dry overnight and in the morning pour a doming layer. Tada… problem solved.

Reply
Melle13

For spot seepage due to the resin leaking into the paper, do the spots get bigger over time?

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Racquel

What happens when you spray polyurethane over a resin coated painting? What reactions can occur?

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amali

hi ,the resin that i use is 100:30 ratio so recently i did two sets but both didnt cur properly i used a butter knife to scoop the resin out from the molds and its cured half way and still rubbery do u think it’ll cure in time to come its been three days now , …

Reply
Katherine

@Amali, if the expected cure time has passed and your pieces are rubbery, giving them more time isn’t going to help.

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John

Will the exposed resin at the top of the mold harden or will it remain tacky – and in that case what can I do to seal and harden the top of the mold.

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John

Thanks – I turn pen blanks and some of them come with a tacky surface which turns away with finishing the blank and I guess those are not acrylic

Thanks.

FYI – I intend to encapsulate butterfly wings in resin – thin sheet – soften the cast and wrap it around a pen tube. The next step is to encapsulate the entire tube butterfly wing wrap and all in clear resin mold (rectangle), harden, turn on a lathe, and voila.

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Megan

This is going to sound crazy but I am in serious need of help. I have been working on a large piece but have never used resin before. I am familiar with silicone, and assumed it would be a similar process. Instead of doing a test, as the manufacturer recommended I jumped straight into the large piece, miscalculated the amount of hardener for the first batch which leaked out of the 2m long wooden container onto my studio floor. The space has terrible ventilation and the fumes are intoxicating. In a completely misguided attempt to conceal the fumes I layered wet clay on top of the wet resin, which has obviously made my problems worse. I have now tried to scrape the clay off the floor and have poured the remaining hardener, a significant amount, onto the floor in an attempt to get rid of the fumes, and for some unfortunate reason I poured a considerable amount of water into the mix. Having read the comments on this site I now realize what a foolish decision that was. I’m not sure exactly what type of resin I have been using but since it was for a large table I would assume it is a polyester resin as it dries very hard with a slightly tacky surface. I have tried cleaning the wet resin with acetone but that does not seem to help, especially with the fumes and my throat is now raw from inhaling the fumes. Is there any advice you can give me that can help me clean/dry the resin to eliminate the fumes? I would prefer not to use any more toxic chemicals but would appreciate any suggestions.

Reply
Katherine Swift

Hi Megan, assuming you are using a polyester resin, those fumes can last a long time. You need to completely open up your studio and get as many fans as possible to get the fumes out of there. The only way I can see getting the mess out/off of the floor is for someone (like a contractor) to sand it down. That is going to require that person to wear the appropriate protective gear in addition to properly disposing of the waste. With any luck, you may be able to use a crowbar (or something similar) and a mallet to dry to break up the resin. (It’s the technique you would use trying to get tiles off a floor.)

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Shannon Miller

I was wondering if there was an easy way to remove metal charms from resin cabochons that you screw up? Sometimes my resin doesn’t set properly and I’d hate to waste the charms I’ve dropped in the resin. Any help would be much appreciated.

Reply
Katherine Swift

If the resin is completely cured, I’m afraid you are out of luck. If it is still syrup-y, you can try soaking in acetone.

Reply
Osmar vasch

Hi,

I got confuse about this;
Make sure you mix the minimum amount of resin needed for the chemical reaction of curing to occur. For example, if you’re working with a 1:1 resin to hardener resin kit, you cannot mix two drops of resin to two drops of hardener and expect it to cure. Resin curing is a chemical reaction that requires a minimum amount of each component for it to occur.

How this can be if the ratio is 1:1, I cannot measu equally ???

Also, instead of leaving the resin in warm water, it not should be better if I warm it up in the micro wave for few seconds?

Thanks a lot

Osmar

Reply
Katherine Swift

Hi Osmar, mixing together two drops of resin and two drops of hardener are unlikely to produce enough heat to allow curing. You will need to ask the manufacturer the minimum amount of each, i.e. 5 ml of each for example, that you will need to mix in order for curing to occur. I would not warm up the resin in the microwave as that may get it too hot in spots.

Reply
Adriana

Hi I’m in trouble! I need your help! I am making cubical crystal clear resin awards. But before I take the piece out omg the mold the resin crashes inside. It brokes when it is still hot, I don’t know what Am I doing wrong 🙁

Reply
Katherine Swift

It sounds like the resin is getting too hot. Are you mixing no more at once than the manufacturer recommends?

Reply
Adriana

yes, actually I reduce the amount of the catalyst. But I get the same problem.

Reply
ImHelping

do not worry! When resin heats up it will cure faster but still give it a day to fully cure. It wont effect the outcome it will just get very hot but once it cures it will start cooling down.

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Katherine Swift

I wouldn’t say that quick heating doesn’t affect the final outcome. Sometimes these pieces can crack or get a ton of microbubbles that will make the final casting cloudy.

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Jerry Jones

I am trying to pour resin in a small glass bowl with a rose into to make a paper weight I have dried flowers but the minute the resin starts to set up the flower turns brown help

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Shannon Miller

I read somewhere about sealing flowers, plants, or candy with something, but i can’t remember exactly where I saw it

Reply
Laura D

HI

Just a question – do all mouldy need to be plastic or silicone or is it possible to use aluminium mounds e.g. Old fashioned jelly moulds?
Thanks

Reply
Katherine Swift

I have not tried them for resin molds. Resin likes to stick to metal, so you would definitely need to use a good mold release. Even then, I question whether or not the mold is flexible enough to release resin.

Reply
Robin

I need help recently started pu resin on the paintings but as it dries valleys appear where resin has separated I try to push more resin back on to those areas but doesn’t help , what am I doing wrong?

Reply
Janelle Dunfee

The resin doesn’t adhere very well on the edges (the rounded part) it looks like fish eyes the way resin works with silicone but I clean my edges just like the front. Suggestions?

Reply
Janelle Dunfee

I’ve used Marine epoxy, Countertop (I Dont remember the brands) and as of late Art Resin. I get the same average with all of them.

Reply
Katherine Swift

So the good news is that you are using doming resins, which should work. Unfortunately though, it sounds like your edges are a little too curved for the resin to want to stay. Have you tried creating a tape dam around your edges to help keep the resin in when you pour?

Reply
Christin Davies

I have never been able to stir my resin and not get air bubbles in it. How do you do that? I do the same thing you do in the video.

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Heather Stanworth

I have some glassine paper stuck to my resin painting. Any idea how to remove it please?

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Sierra

Ok I know this is trouble shooting resin but I need a more experienced view. I took some resin pieces that I was going to throw away to school. People really liked them and I got commissions. I got into resin a month or two ago and most of my pieces turn out pretty good, save for the occasional tackiness and bubbles. I’m not trying to market them as professional quality and I tell people this but I’m worried that I might be getting over my head. I don’t know if I should do the commissions and stop or try to get more. Do you have an opinion?

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Cindy

Thanks for all your tips. I’m new to resin but I noticed on my 2 resin pieces, canvas and wood panel that they both end up with less resin on all edges. I leveled them and I’m puzzled why this is happening? Tks

Reply
Cindy

Thank you Katherine for all the great info. For 12×12 I used 5oz for top n sides. Should I re-do and extend painters tape up n above edges to hold resin in? I love the all over look though but willing to giv it up.

Reply
Cindy

PS I hav a tip I wld like to share. Vaseline works great where u don’t want resin. It peels right off. I used it on my underside edge of my wood panel b4 I resined.

Reply
Chloe

Im using Smooth Cast 305, i measured everything right but it hasnt cured properly and is soft and there is some excess oils. Ive taken my casts out of the molds but there is some oils and rough bits of resin left behind. Whats the best way to clean the molds out?

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Jenny

Hi, please could I ask for some help. Many years ago I poured resin (over paper pictures) on the bottom of a tray. I have now found out that the painting under the resin and paper was done by my grandmother. I want to know if there is any way of now removing this resin, after all this time, without destroying the painting underneath. Thanks.

Reply
Katherine Swift

Unfortunately I don’t know of a way of removing the resin where the painting won’t be damaged as well.

Reply
Jenny

Is there anything I could try though? (obviously with no guarantees, but just to try?

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Gerry Berger

We got some furniture resin hardener on a couch….how can I clean the couch?

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Tina

I am casting in a silicone mold. The top part comes out crystal clear but the bottoms and sides are dull. Any idea why? I am using a mold release and made sure it was completely dry before I poured.

Thanks!

Reply
Kayla

Hi I have done an acrylic pour painting on a stretched canvas. I used silicone in some of the paint. I used the product Glaze Coat High Gloss Craft Resin. I mixed 1:1, stirred for 6 minutes and all of that.
The result I got is blocky. It resembles what happens if you were to spill Sprite or 7-up on a table and let it dry. The surface is smooth to the touch and not tacky. It just looks like a Sprite spill… any advice?

Reply
Katherine Swift

Hi Kayla, it sounds like you have some divots in your surface. Do I understand that correctly?

Reply
Kayla

I am attaching a pic as I am not sure what it’s called when this happens.

[IMG]http://i64.tinypic.com/290s9z7.png[/IMG]

Reply
Katherine Swift

Hi Kayla, it looks like ‘fish eyes’. Did you wash your painting surface before applying resin? Silicone leaves behind a residue that can push away resin.

Reply
Kayla

I was not aware of that step. How does one wash a painting?

Katherine Swift

Use a good detergent (I like Dawn dish soap) and allow to throughly dry. Some will go the extra step of rubbing down with alcohol to remove any remaining residue. Allow to fully dry before applying more resin.

Brian

I’m trying to set a piece of fruit in a resin block, but the temperature of the resin burns the fruit as it set, leaving a black burnt mess inside. Can you help?

Reply
Katherine Swift

Hi Brian, I want to help you with your project, and I think this situation is best suited for a one-on-one consulting call where you and I talk back and forth about what’s going on. I can set you up for a 15 minute consultation call. If you want to send an email through our contact page, I am happy to respond with prices and availability.

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Eric Restorat

Hello ~
I just had a question regarding a problem I’ve encountered trying to use EnviroTex Lite Pour-On Resin.. (I have a photo to illustrate my issue, but I am unable to attach a photo to this message). Basically my issue is that when the product dries, it will ‘retract’ in certain areas and not dry smooth… (I call it the “Freddy Krueger effect”). Please note that I am also pouring on top of an already resin surface, (in an attempt to ‘restore’ or cover blemishes), but I have sanded the surface prior to use (1000 grit). I will also use a propane torch to eliminate the tiny air bubbles.. yet somehow, I am unable to successfully get it to cure smoothly. Any advice/tips as to why this may be occurring or what I may be doing wrong is greatly appreciated!
Thank you!

Reply
Tooba

Hi Katherine,
Great article, thanks!

I’m preserving dry flowers in resin using spherical molds and my first batch was awesome. However the second batch became a goopy mess inside the sphere, like I can press the ball on the surface and feel the softness inside.

I think I might have not mixed enough (3 minutes according to the instructions) or the temperature might have decreased because I live in a warm country and I turned on the AC in the middle of my process.

I have a question regarding resin curing. When I pour the resin on many tiny flowers, they rise to the top and I continuously poke them so they stay inside. Does that mess with the resin curing? Could this be a reason why my resin was goopy? Plus if I fill the resin mold in 2 parts to solve this issue, meaning I fill half the mold with resin and flowers and let it dry, then I mix more resin and pour it on the top, will it be a problem for curing resin?

Thank you very much,
Tooba.

Reply
Katherine Swift

Hi Tooba, it sounds like you are working hard to get your resin and flowers to work together. Awesome! I want to help you with your project, and I think this situation is best suited for a one-on-one consulting call where you and I talk back and forth about what’s going on. A 15-minute consultation call is $20. I do them by video so I can have a chance to see what you are working on.

If you are interested, please send a message through the ‘contact us’ page and I can get this going for you. Best, Katherine

Reply

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