Thread: Lessons in casting

OK now that I've finished, here's the final lesson for the day

11. If life gives you lemons, make Lemonade!

Russell.

But what is it?

Originally Posted by funkychicken

But what is it?

What's what? The pen, or Lemonade?

If you mean the pen, it's a Streamline done with my first cast blank (Bunning Clear Casting Resin), made with all the bad stuff I mentioned in my first post (yes, it even glows in the dark - a little at least, and I didn't mention the god awful glitter paint as well), patched up as best I could before it got too dark, then sanded to 1200 W&D, MM to 12000 dry (needed my MM, so couldn't wet it) and brasso'd to finish. Crappy picture taken under bad light, at night with a flash.

Considering things couldn't get much worse than all that, I'm quite pleased with the result.

Russell.

Didn't NASA put one of them into orbit

I'm very impressed - been turning for about a sparrows f**t and you're already casting your own blanks. Blooming amazing

Looks OK to me. Good effort.

Terry

Well Russell you may have had some trials and tribulations but the end result look ok for the first one.

I went through the same process and have a lot of useless blanks where the pigment did not gel with the resin. It becomes expensive so stay with proven pigments now.

Happy casting

Originally Posted by BoomerangInfo

Thought I'd pass on some of my experiences from my first abysmal attempt at casting : -

1. There's going to be a lot of wasted materials before I get it right
2. Crazy Clarks poster paints make terrible pigments This is due to the fact most of these poster paints are water based Water and resin "Do Not Mix"
3. Crazy Clarks "Glow In The Dark" paint and Resin hate each other Same as above with the one I have seen in this store.
4. It only takes 1 air bubble to ruin a whole blank Bubbles can be removed using a stippling brush or even a long hat pin. Pouring very slowly into the casting vessel helps almost as though your sliding it in.
5. Getting the catalyst mixed properly is critical Yep ambient temp, humidity, surface being worked container your pouring into all effect gelling time. If I can dig up some old notes I'll post the relevant info.
6. Patience is a virtue
7. Bunnings MEKP is expensive!!
8. Ventilation is important Extreamly many a sufboard maker has been found past out.
9. Trying to fix a bad result, only makes it worse It can e done
10. Chip happens

and I'm only half-way through the process yet....

Russell.

Russell there are poster paints and glow in the dark that are acrylic (just make sure once again they are not water based) sold at such as Crazy Clark's, Warehouse, etc these will mix with resin as will car paints, nail polishes.

These should be mixed prior allowing to settle then adding MEKP, mixing that to a slow setting so that you have to for working it. The higher the ambient temp the less MEKP.

When mixing Resin & hardner it can be mixed to get so hot it can cause fires.

Ray

Thanks Ray,

I think my biggest problem came from either my initial catalyst addition, or some reaction with the poster paint. I suspect I didn't stir the hardener sufficiently, but what happened was I coloured half a batch, and poured it into the mould, then coloured the second batch, tried to pour it on the first batch and swirl.

Well, when I tried swirling, the whole middle of the first batch had set to a thick gel already (no more than 3 minutes from when poured) and as I tried to stir, I dug up great lumps of it. Then it took about 2 days for the outer surfaces to dry completely.

My second batch I poured seemed to be much better consistency. I realised when I was about to start it, that I have a selection of acrylic paints I bought to airbrush T-Shirts, and it seems to have mixed pretty well. I admit I did hurry the storring, as I was afraid I'd get the gel problem of the first batch again. I'm yet to try turning this second batch to see how it's turned out, but it looks and feels much better in the mould.

And as for #9, yes I think I did do an Ok job of fixing the few voids I struck int hat first lot. Luckily, being mostly white, the fill just blends in with the rest of the blank. If I'd chosen a darker colour it might not have worked so well.

Oh another question. I was just in the local hardware. What's the different between clear casting resin, and fibreglass resin? Anyone know?

Russell.

Russell if you have mixed one lot then poured a 2nd mix on top thats trouble as the first is already having a reaction heating up .

Pouring the second batch on as a new mix is what the problem was. I have seen this cause fire when I was working with resins and fibreglass. If not fire it gets hot enough to burn skin.

I suggest you pour your resin and colourings into your form stir let settle a bit, then add catalyst stir gently (from memory we used a left right motion keeping the stick flat face not twisting ) but thoroughly use a flat stick try not to create air bubbles.

In this heat much less catalyst is required.

I try use either a medicine cup to measure or a syringe.

Originally Posted by wheelinround

I suggest you pour your resin and colourings into your form stir let settle a bit, then add catalyst stir gently

But doing that, there would be no way to keep your colours separate to get swirl effects, as to thoroughly mix the catalyst would thoroughly mix the colours too, wouldn't it? Or doesn't the catalyst have to be thoroughly mixed through? Maybe I'm missing something obvious here.

Russell.

oopps its a two part motion that way I was thinking you were doing a solid colour then adding swirls not clear then adding swirls

have added a pdf I found some time ago

Thanks.

I've read all the casting tutorials I can find, but hadn't seen this one.

Russell.

Russell, I buy my resin, MEKP and pigments from Barnes (their site is closed for maintenance at present so can't put up a link, but Google will find them).

They sell 2 Polyester Resins, Clear Casting and Quality Casting. The Clear is dearer and the Quality is an amber colour, which doesn't matter if you are pigmenting anyway.

They have a range of pre-dispersed pigments (about $9 for 100gr), MEKP (about 1/4 of the price of Bunnings and a range of other extenders and metal powders.

They also sell Pearlex pigments.

I shop in person in Richmond Vic, picked up 4 ltrs Quality Casting Resin for $30 yesterday (they sell cans close to expiry date for around half price).

Air bubbles are minimized by using a pressure pot (SperCheap Auto, plenty of threads in the pen forum).

As wheelin said waterbased paints (not pigments) do not mix with PR, nor do tubes of artisst acrylics or oil paints.