The random RESIN question thread!

[emopoops]

i read that u wet sand the jewelry with fine grit sandpaper (wetordry)
for whatever reason.

and then my question is about after you wet sand it or whatever even if its not sanded and its just fresh out of a gem mold,
what are u supposed to do to make it like scratch resistant?

can u actually put car polish on it? like if i wanted to make a resin gem and the drilled a hole in it for a necklace and just stringed it on a chain with no backing or anything i want the thing to shine. it has to be shiny and smooth and mirror like... kind of like cars. but how do i make this happen?
 i know that i have to sand the back of the piece because of what happens in the curing process(shrinks) and how it doesnt cure flat(looks like a spoon/bowel on the top when its in the mold)

 so i sand that so its straight and no bowl shape. then how do i get the entire piece to be scratch resistant?

because resin scratches so easily.
i want it to like stay smooth and scratch resistant and glossy shiny for like ever how do i get it to be that way?

what do i use?

[Bellazeus]

Im no expert... ive only just started playing with it.. but i have read that brasso shines it up beautifully and that alot of people varnish over the top of resin .. but i dont know with what type exactly.. hope you get your answers!!

[PinkyK]

Here are some magnets I did in an ice tray, castin craft resin and green glitter. There is glitter through out the entire magnet it did not settle on the bottom. I attribute that to the massive amount of glitter I used. The only problem is the green coloring from the glitter ran a bit and colored the resin green. It turned out fine for this project but for another project it may have been a problem. I dd the same thing in silver, gold and red and it worked in exactly the same way.


The back of the magnets


The front of the magents


The front of the magents


The front of the magents

[Diane B.]

If you want the resin to be more scratch resistant, the only thing I know to do is coat it with clear polyurethane (it's tougher than just about any other clear medium).

You can always rebuff (or sand and re-buff) any areas that aren't clear to achieve or bring back the highest gloss, but don't know that there's any way to make it high-gloss forever unless you at least use the polyurethane coat (and even that could require attention if it's subjected to a load of stress/scratchy stuff).

Some kinds of paste wax can be used if the surface is smooth enough, then polished....for more info on waxes and coating, check out this page:
http://www.glassattic.com/polymer/other_materials.htm

Polyester resins will be a more brittle and less hard than epoxy resins too (Easy Cast probably in-between the two), and the side of polyester resin that cured next to the air may be a bit cloudy or uneven.  Polyester resins will also shrink from the sides more so more often need sanding. If you used a polyester resin, you could get a bit more strength and clarity by coating it with an epoxy resin (or either can have the polyurethane on top).

[ammasmama]

PinkyK's right, and Pinky, the color only bleeds with certain brands of glitter, I remember a veeeery annoying purple! Then again I only use fine glitter, almost too thick stir...

[tinkxoxo]

so just an update on where I'm at Ive taken the time i have free for the Easter break and decided to finally use the resin Ive bought



and added it to some rubber ice cube trays - i made sure followed the directions 100ml of resin and 35 drops of hardener and added lots of random things to the moulds as it was my first time i just wanted to see the effect - i mainly realised most things (beads etc) sank which for some reason i wasn't expecting.



i waited 24hrs although the instructions said it would harden within 3hrs and when i took the casts out although i didn't have much trouble removing them i now have a very tarnished front  and i suppose i could describe the whole 'cube' as very sticky and still smelling very toxic

i just thought id give you all an update on how i was progressing seems as you've all be so helpful and i hope to get used to this resin thing soon and I'm planning on buying a one of the more popular brands when i get the hang of it.

[Diane B.]

i made sure followed the directions 100ml of resin and 35 drops of hardener and added lots of random things to the moulds as it was my first time i just wanted to see the effect

. . . i hope to get used to this resin thing soon and I'm planning on buying a one of the more popular brands when i get the hang of it.

So it looks for sure like you purchased a polyester resin, not an epoxy resin.  
Be aware though that with polyester resin, it isn't always as simple as adding the exact number of drops every time since the amount of catalyst needed for those kinds of resins can vary with humidity, temperature, thickness, etc. (which is mostly not true for epoxy resins).

Also, polyester and epoxy resins are different enough that you can't count on applying everything you learn from one to using the other (would be better just to start with the kind you think will work best for what you want to do... in your case of casting in shallow molds, that would be Easy Cast if you didn't mind it's disadvantages, or a regular epoxy resin).

- i mainly realised most things (beads etc) sank which for some reason i wasn't expecting.

i waited 24hrs although the instructions said it would harden within 3hrs. . .

Anything heavier than the resin will sink in it until the resin gels at least a little... that could have been the 3 hrs the instructions mentioned it "hardening" within (so items could be added, then more resin poured over them), but generally gelling doesn't necessarily take that long.
 
And usually, it's a full 24 hrs of curing before most resins should be removed from their molds (when using molds).

and added it to some rubber ice cube trays . . . when i took the casts out although i didn't have much trouble removing them i now have a very tarnished front   and i suppose i could describe the whole 'cube' as very sticky and still smelling very toxic

About the "toxic smell," that's because you used a polyester resin.  Epoxies have little odor (and are safer for breathing), and the tweaked epoxy Easy Cast has even less, I think.

About your molds though, several things could be going on.
 
Remember that polyester resins won't thoroughly cure in the presence of air...they'll often feel sticky or be somewhat cloudy on those areas. (That's intentional btw, so that the fiberglass cloth or just the next layer of resin will stick to it better --polyester resins aren't as naturally adhesive as epoxy resins.)

So it's possible that any stickiness or non-clarity of your pieces was because you removed the resin too soon if the those conditions were on all sides of the piece --though the back side of a cast made in a mold with polyester resin might always be that way (where it had been in contact with air) unless it's sanded then buffed after curing, or has a layer of epoxy resin put on it.

I don't know what "tarnished" means in this case though. Do you just mean "not perfect"? ...or do you mean that it had a tarnish color?  
If you meant just "not perfect," then it could be that the ice cube tray depressions weren't very-very-smooth (from tiny scratches, perhaps not even visible) which will mean that the suface of the resin formed there is also not very-very smooth and so shiny once cured.  Or it could have to do with the stuff mentioned in the previous paragraph.
If you meant a tarnish color, it could be that some of your embedments bled (some must be sealed before embedding), or if brownish, could mean that the resin got too hot during its curing period (that could make it yellowish, and perhaps even brownish?)


Diane B.

[mei]

Argh! I'm getting really bummed out with my resin! I use Easy Cast by Castin Craft resin and I can't seem to get it right.

I've tried it about 4 times already and so far I've learnt things along the way. I know that I have to mix the resin in equal parts (no estimating!) which I do with measuring spoons. I know that you have have have to "double mix" and I do. I also spray mold release on my silicone putty molds before pouring in the resin.


The problems I have are:
1) My resin forms bubbles at the base of the mold. I use a hairdryer to try to get rid of them as I've read in this thread, but I sit there for a good 10 minutes and the bubbles are still there!

2) Once hardened, the bubbles all form at the base and it looks cloudy. I just can't seem to create that crystal clear resin you guys seem to be able to get right!

Poopsies

[Diane B.]

Not sure what's happening but don't know that silicone molds always need a release.

Bubbles are normal and they should rise for about 10 minutes after pouring but not sure about their all collecting at the bottom of the mold --is that what you mean by the "base"?  Most would generally rise to the uppermost areas, gravity-wise.
(And btw, you should be able to use your breath --through a straw if you want-- to pop the bubbles after they really start coming up, or to pass a lighted match over them. Both those create the carbon dioxide needed for popping, but won't blow dust around which can settle on the resin. You don't need to pop them all right from their first appearance, and many will pop on their own as the resin heats up.  A toothpick can also be used for to physically burst larger bubbles.)

Other possible causes?

...Make sure resin isn't too cool when mixing (which can create extra bubbles and later cloudiness).  If necessary, warm it by putting the bottles into container of warm/hot water for few minutes (should feel just warm to the touch, 70-85 F).
...Moisture in the resin which may come from humidity in the air or from unsealed embedments, can cause the resin or the casting to be cloudy. Also keep resin capped tightly when not in use.
...Are you using any inclusions that might be have trapped air, or contain any moisture?  
...Don't use waxed paper cups for mixing since that can also make resin cloudy. And what are your stirring sticks made from?
...Some people also recommend a whipping action rather than "stirring" to keep from incorporating too much air.
...One person also recommends pouring the resin from the cup (into another container or a squeeze bottle) slowly, which may reduce some of the bubbles.  Letting the resin run down the side during pouring may be helpful too.
...Scratches (even hard to see ones) on the surface of a mold will cause cloudiness because the surface isn't thoroughly smooth.  Which brand of 2-part silicone putty did you use, and did you make it *very* smooth (some brands, e.g., don't really end up with very smooth surfaces, like the Amazing Mold Putty I hear).  It's even recommended not to "wipe" molds dry, even the HDPE ones made for resin casting, since that can scratch them --instead, air-dry.

(Will write more if other variables occur to me, but there's also lots of info on my resins page:
http://www.glassattic.com/polymer/other_materials.htm )

Diane B.

[mei]

Not sure what's happening but don't know that silicone molds always need a release.

Bubbles are normal and they should rise for about 10 minutes after pouring but not sure about their all collecting at the bottom of the mold --is that what you mean by the "base"?  Most would generally rise to the uppermost areas, gravity-wise.
(And btw, you should be able to use your breath --through a straw if you want-- to pop the bubbles after they really start coming up, or to pass a lighted match over them. Both those create the carbon dioxide needed for popping, but won't blow dust around which can settle on the resin. You don't need to pop them all right from their first appearance, and many will pop on their own as the resin heats up.  A toothpick can also be used for larger bubbles.)

Other possibilities?:

Make sure resin isn't too cool when mixing (which can create extra bubbles and later cloudiness).  If necessary, warm by putting the bottles into container of warm/hot water for few minutes... should feel just warm to the touch (70-85 F).
Moisture in the resin, which may come from humidity in the air or from unsealed embedments, can cause the resin or casting to be cloudy.....keep resin capped tightly when not in use.
Are you using any inclusions that might be have trapped air, or contain any moisture?  
Don't use waxed cups for mixing since that can also make resin cloudy. And what are your stirring sticks made from?
Some people also recommend a whipping action rather than "stirring" to keep from incorporating too much air.
One person also recommended pouring the resin from the cup (into another container or a squeeze bottle) slowly which may reduce some of the bubbles.
Just having scratches (even hard to see ones) in a mold will cause cloudiness because the surface isn't thoroughly smooth.  Which brand of 2-part silicone putty did you use, and did you make it *very* smooth (some brands, e.g., don't really end up with very smooth surfaces, like the Amazing Mold Putty I hear).  It's even recommended not to "wipe" molds dry, even the HDPE ones made for resin casting, since that can scratch them --instead, air-dry.
(Will write more if other variables occur to me, but there's also lots of info on my resins page:
http://www.glassattic.com/polymer/other_materials.htm )

Diane B.

Yup! I read up about how bubbles will be normal and that with Easy Cast resin, it will automatically degas itself. That wasn't the case with me though! Yes, the bubbles collect at the bottom of the base. I am trying to make 1 inch resin domes with CastinCraft Easy Mold.

When I used my hairdryer on the resin to release the bubbles, I saw some raise to the top and disappear VERY slowly. But most hang around at the bottom and they seem stationary :O

I did warm up the bottles before I used them, and they felt warm to the touch so I'm sure I did that right! I worry that maybe with the small amounts that I use, they just end up cooling down while they're exposed to air for the 3 minutes of mixing and double mixing.

I use non-wax cups and my mixing sticks are the wooden popsicle kinds.

At the moment I can guess that the molds are probably the cause of the cloudiness and bubbles. There are probably teeny tiny scratches on them that I can't see, but it seems likely for them to be there!