[Katherine Swift]

Hi Pat,

A few comments regarding your situation.

1. I have had good luck with ‘like adhering to like’, even if they were different brands. For example, I have used one brand’s epoxy on another brand’s epoxy and have not had problems with things adhering. From what I know about polyester and epoxy, I would expect it to work there too, assuming the first layer had completely cured. I haven’t specifically tried this though, so proceed with caution.

2. As for the wood, epoxy would be my choice to use in this project. Polyester resin will shrink too much after curing. It may even shrink so much it doesn’t stick to the wood! Polyurethanes can be used with wood, but your wood will need to be dry and sealed first. Polyurethanes hate moisture.

3. As for ‘seamlessly’, yes, they will attach, but a seam may show depending on how you color it, if you color it, etc. Pouring the next layer while the first layer is curing will minimize the seam.

Good luck!

[Diane]

Hi, I have questions. When making a piece that involves several layers of resin, which require fully curing each layer before adding the next, would you wear a ventilator mask during the entire process? If you want to draw on a fully cured layer or apply some kind of artwork to it with pen or brush, still need to wear a ventilator mask while doing that? Thanks.

[Katherine Swift]

Hi Bev,

If you are referring to a two part resin (not a UV activated resin), then no, the Part A will not cure on its own. It needs the Part B hardener mixed with it to create heat. That heat is what causes curing.

[Katherine Swift]

Hi Matt,

If you are using epoxy resin for your wood pieces, it will not withstand the heat of a belt sander. Unfortunately, the softening you see happens pretty commonly. Polyester resin cures hard enough for use with rotary tools, but the shrinkage after curing generally makes it unsuitable for use with wood. Your best bet would be a polyurethane resin.

[Katherine Swift]

Hi Lori,

What happened is that the resin cured next to the wax paper. Wax paper is great in that resin doesn’t stick to it, but it does leave this mark. You can try recoating with another layer of resin, but you will most likely see the frosty surface underneath. You can try sanding the surface with a wet/dry sandpaper. Start with a 400 grit and work your way down to a 1000 grit or higher paper. You can recoat with resin then and should not be able to see the blemish.

It’s good that you want to cover your pieces during curing as dirt and dust will get into it in no time! In the future, I would suggest using plastic domes (large food containers or plastic totes work well) to cover your pieces.

[Katherine Swift]

Hi Misty,

There could be a few things going on here. First and foremost, you need to be sure you measure accurately and mix thoroughly. You also need to mix the appropriate minimum (based upon the resin you are using) to make sure enough heat is generated to induce curing. I don’t know how thin your resin layers are, but thin layers can also be a bigger challenge to cure since the heat is spread out over a large area.

Assuming all the above things were done correctly, my next suspicion is that the acrylic paint kept the resin from curing. Resin hates moisture! The powdered metal and Pearl Ex are not likely the problem as they are dry powders.

Every resin is different in its cure times, mixing minimums, etc., so it wouldn’t be a bad idea either to make sure you have all the basics covered.

We have some other troubleshooting articles as well that may give you some other ideas on what to do differently: https://resinobsession.com/tag/troubleshooting

[Katherine Swift]

This is a response my friend Charlie who has a lot more experience than I do working with wood and resin:

I haven’t really fixed in my head what he’s going for yet, but a few things come to mind as I read it..

I’m not sure about the cellophane part, so I can’t really comment on that. And when he talks about layering, he’s right to mention a ‘clear pour’ .. if there’s anything in the resin (like glitter) it will probably highlight the line between layers.

I don’t know that I’d ‘scuff up’ the resin before layering .. the resin will either bond or it won’t. Scuffing won’t really help and could show up as a line.

Bubbles .. the bane of our existence!
I know many casters who quote Boyle’s law and think they’re going to compress the air bubbles in the resin till they’re invisible.. but it just won’t happen without some heavy duty commercial equipment.

Most pressure pots available to consumers are rated in the 50-60psi range .. or 3.5 to 4 atmospheres. That means that even if you push the pressure up as high as safely permissible, those are bubbles are about 1/4 their original size. That’s still highly visible.

So rather than look for ways to hide the air bubbles, I’d be looking for ways to stop them from occurring in the first place.

I’m not sure if the air is getting mixed in because of vigorous stirring or perhaps there is a chemical reaction going on because of incomplete curing of the sealer. Just because the sealer is dry doesn’t mean it is ‘cured’ .. often finishes can take a month or more to fully cure, and during that time they can (they will! ) release gasses and be vulnerable to chemical reaction. There could also be incompatible materials under the resin besides the sealer.

Vacuum can only help so much in clearing bubbles. It is better than nothing, but not ideal. It does make the bubbles larger and easier to pop. But thinking that it makes them rise faster because there’s “more air” in them is incorrect, too. (Boyle’s law, again) Under vacuum, those bubbles still contain the same amount of mass, it is simply spread out over more area.

He mentions ‘driving the epoxy into the wood’ when using pressure.. but that should only be a concern if the sealer isn’t cured yet. Once hardened, we’re not talking about so much pressure that it would penetrate a cured finish. (unless he’s using some high pressure equipment)

If I were trying this, I’d use my old stand-by routines.. fully cured finish on the wood (even if it takes 4-6 weeks!) gentle stirring and a gently warmed resin so it flows and the bubbles (if any) are free to rise to the top.
But .. not seeing the project, maybe I’m all wrong, too!

[Clinton Gallagher @tapABILITIES]

Jerry, fill those three drilled mounting holes with modeling clay to keep them free of resin.

Katherine is right about bonding to metal although I would suggest also drilling several little 1/16″ or 3/32″ holes as sanding in that little space will hepl a bit but you want to allow the resin to seep into the little holes you drill to “key” the resin to the piece creating a sturdy friction fit which will impose resistance to airflow and drag over the piece that may otherwise suck the resin out of the piece during flight if it were just sanded up a bit which would only be neccessary in circumstances where extrenal forces are not involved.

IMO I would not POUR the resin into the piece. I suggest buying those little white plastic mixing stick paddles Katherine sells and using the paddle end to DRIP the resin into place (nd toothpicks too) giving you complete control of how much resin you use to control your dome and also using the tip of the paddle and toothpick to help the resin flow into corners, tight spaces and your key holes.

I might argue a bit and suggest using polyester resin as you may not want a dome on the finsihed piece which may remain after the cure because polyester shrinks into a convex (or flat) top surface when curing so if using polyester resin you dome when wet and it will flatten out during the cure. This is a but touch and go. Google: polyester resin vs alumilite and watch some YouTube videos. Katherine sells a polyester from CastinCraft as I recall and it too can be made opaque my only point being if you really want the resin to dome after cured which may conflict with the prominance of B55 which I somehow have the thought you want to remain prominent.

Either way because you are going to DRIP you can retain complete control of how much resin enters the void and simply hold back from filling to the top surface of the B55 characters. A very thin layer of resin will work just as well because you are key locking the resin to the piece.

[Katherine Swift]

Safer in what way? The finished product? When mixing polyurethanes, they can more dangerous than epoxy as some require special breathing equipment.

Polyurethane is going to drip as well. You can try a quick curing polyurethane, but you have to be ready to brush it and keep your piece moving. You may still have some drips, but at least you will do less babysitting of your resin. 🙂

[Katherine Swift]

Hi Kathie,

For this project, I would not use a polyester resin. The surface exposed to air during curing will remain tacky, so it’s one more step to have to deal with. I also not aware of a ‘small scale crafting’ acrylic resin for your project. That leaves an epoxy for your table. I would use the Resin Obsession artwork resin. You can buy it in our store here: https://shop.resinobsession.com/collections/resin/resin-obsession-artwork-resin

[Katherine Swift]

Hi Kim,

Two things that might give you trouble:

1. I don’t know how well the plastic will tolerate the heat of the resin curing. If you want to try, I would cast it somewhere you can easily capture a mess should the resin eat through the plastic.

2. A mold release is definitely necessary for casting in this. Even then, I don’t know if you will be able to get it out. You can see what happened when I tried casting resin in a thin plastic soap mold: https://resinobsession.com/molds-mold-making/casting-resin-in-a-soap-mold

As for what you can do with it, I can see it being a neat looking light pull. You could also try drilling it so that you could use it to string lights. Imagine drilling horizontally through the base, then drilling perpendicular to that up through the bulb. Maybe then you could pass Christmas tree lights through them to help light them up. If you are only casting a ‘half’ light bulb, you could put a light behind it.

[Katherine Swift]

Hi Monica,

I’m happy to hear you are having fun with resin casting. Enjoy the journey!

Polyester resin can be tricky to work with and I generally don’t recommend it for beginners. When it comes to adding catalyst to the resin, you have to start with the end in mind. You add drops of hardener based upon the thickness of the final casting. How deep are your spheres? That will dictate how much catalyst you need. The ironic thing about polyester casting is that the thinner the casting, the more catalyst you need to generate enough heat to allow resin curing to occur.

The issues with your heart-shaped silicone mold is likely due to the mold. Castings will pick up the surface of the mold and impart them on the casting. If shiny templates weren’t used to make the mold, castings from that mold won’t be shiny either.

As for your castings, I think they are getting too hot and subsequently cracking. If you can tell me how deep your castings are, I can help you tweak the amount of hardener you use. Your room is a little warm (72 or so is ideal), which may also be impacting the heating up and subsequent cracking.

Have you considered an epoxy resin? I like polyester resin for larger castings, but based upon your description and the pictures you sent separately, I think getting polyester to work in this situation is going to be a challenge. (Plus the smell is horrible.)

[leah]

in my limited experience, depending on the type of resin you use, the ventilation is not 100% required. i have a small house and do my resin projects on my dining room table since it’s the most open area in our house (which is a pain in the winter because it’s also one of the more difficult rooms to keep warm). since i use only the low-odor epoxy resins, it seems to be just fine, at least in regards to the smell.

getting resin on my skin, on the other hand, i am extremely careful about. when i first started using resin (easy cast), i tried not to get it on my skin but i never wore gloves. and it only took a few times for me to have a reaction, not only to where it touched my skin when i cleaned out the mixing cup for reusal but also wherever the fumes came in contact with my skin (wrists, arms, neck, face) that was miserable lasted over a month. even when i wore a painter’s mask and long sleeves, i’d still have some reaction issues. i’ve since switched resin (had the WORST luck with easy cast curing anyway) and haven’t had as many issues, but now i still always wear gloves and try to avoid holding my arms or face directly over the resin i’ve just poured. so please, please be careful!

[Katherine Swift]

Hi Diana,

Yes, I would recommend the piece stay in a well ventilated area while it is curing as well. Keeping it covered to keep out dust is a good idea and will help a wee bit with the fumes, but until it has reached the demolding time, I would keep the ventilation good in the area. If you have a room that you can dedicate to resin casting, you can leave the room when you are done casting, close the doors, but perhaps leave a window open and use a fan to circulate the air.

If you get resin on your hands, I would recommend washing it off with a good detergent and water. Don’t use alcohol or acetone as this will likely make the irritation worse. I would also suggest making yourself familiar with the SDS information on the resin product you are using. Included are safety measures on how to handle spills, etc. and when to seek medical attention if necessary.

The goggles are important in case the resin splashes in your eyes and when you are sanding. It won’t do much to keep fumes out of your eyes. If that is a concern or you find you are extra sensitive to the fumes, then I would suggest working the resin underneath a ventilation hood which can evacuate fumes away from you while you are working.

We also have a safety section that goes over additional information as well: https://resinobsession.com/tag/safety

[Katherine Swift]

Great questions! While I can’t guarantee that it will completely eliminate lines, pouring the second layer of resin while the first layer is still curing will minimize them. You are correct in that you will need to do it while the first layer of resin is in the gel stage. This is when the resin is starting to cure, but not solid. If you were to place a toothpick in the resin at this point, it will be a thick, and perhaps chunky, liquid. The time for this to occur varies with every resin. Unfortunately, at least the first few times, you are going to have to babysit your resin to see when this occurs. In my experience, it happens within the ‘double the pot time’ range. For example, if the pot time of the resin is 30 minutes, the gel time will likely happen within 60 minutes. The gel time usually only happens for a short period of time, so you are going to have to watch it closely and be ready to pour your next layer.

As for pouring only 1/2 inch at a time, that also depends on the resin. Some have recommendations on thickness of pours, while for others, it’s more about the volume.