First attempt at Polyresin = FAIL

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redneckmedic

redneckmedic

Member
Joined
Dec 15, 2012
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265
Location
Greenfield, IN USA
So I bought the $24 kit from hobby lobby and ordered sampler packs of color from Coastal Scents for $1 per color.

My observations....

It doesn't matter how many videos or threads you read, there is no replacing hands on and olfactory overload. I forgot about the warning of smell and made my blanks in the kitchen... huge mistake and huge headache. When it sets... it sets.

I made two 3/4" pvc tubes with corks in the end 40hrs ago, and they are still wet, I was sure they would have cured by now in a 70 degree house. I used about 5-7 drops of MEK per cup (about 2 ounces).

The next batch I made was a two tone green that I poured into a Aldi's lunch meat container. I figured I could rip on a band saw into 3 separate blanks. I set the two cups a side to thicken up a bit before the pour, cleaned up a bit and came back (less than 2 min) to find a glob in each cup that plopped and not poured. So now I have a mold that is very terrainious on top and smooth on bottom. My big worry is, if I try to pour a third color on the is mold to fill the voids and level off the top, even if I add pressure or vacuum there will still be air pockets inside the hardened mold.
Even with the failure, I learned a ton, and this is a very easy process.

Why hasn't my tube molds set?

What's your advice to try to salvage the block mold. I figure I'll just rip on bandsaw, turn as usual and back fill with CA the pores.

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Whats the difference between dog barf and a blown resin cast...nothing!! The resin and more important the catalyst needs to be fresh!! Other than that...live and learn!!
 
When you say the 3/4 pvc blanks are wet, do you mean liquid, or just sticky? It's not uncommon for the blanks to be sticky for several days. Many of us use a cheap toaster oven to finish curing the outside of the blank. Just set it for about 125 for 20 minutes. 5 drops for 2 ounces is a little light on the catalyst. I usually use at least 3 drops per ounce. If you did 7 drops you should be ok.

On the 2nd pour, I've never heard of PR setting in 2 minutes. I'm far from an expert, but I've probably poured almost 20 gallons, and I've never seen it cure that fast. My normal curing time is about 20 minutes. In the summer it will be faster just because my garage gets pretty hot. Even then, my fastest is about 5 minutes.

Castin craft catalyst does seem to set faster than the stuff from US Composits, but I don't see how you could get it to cure that fast using the ratio you mentioned.

There is definitely a learning curve to casting, and we've all had some set up on us before we expected. And sometimes we get results that far exceed what we expect.
 
There is no saving #2. Pitch and start over. I've poured approximately 2.74 billion gallons of PR and have never ever had it set up that fast. Something went goofy.

On #1, yeah, if it is solid, but tacky, toaster oven is a good way to go. If they're still mushy, more catalyst next time.

EVERYTHING is a variable that matters with PR. Temperature, humidity, catalyst amount, PR age, catalyst age, type and amount of colorants, volume of lint in belly button. You just have to suffer through the bad times and, soon, you'll start to suffer through the good times:biggrin:.
 
InvisibleMan said:
EVERYTHING is a variable that matters with PR. Temperature, humidity, catalyst amount, PR age, catalyst age, type and amount of colorants, volume of lint in belly button. You just have to suffer through the bad times and, soon, you'll start to suffer through the good times:biggrin:.
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Dang!?!?! I knew there was a secret.:rolleyes:
 
If it were me I would throw out the blob of PR and not try to save it, and then keep a closer eye on it the next time I made some. The pvc cast should be set but I would probably wait another night then try to punch it out to see if it is ok. I think the normal amout of MEPK is 3-4 drops per ounce. I use 4 drops and haven't had any problems for a long time.

I have made mistakes and had to throw some out so you''re about normal, I would say.

Just keep trying and you'll get it.
 
I'm thinking to cut into your solid blob and see what you have. Cut some squares long enough, for maybe the sierra, then turn them round and do a quick polish to see what you have. If it's anything that looks good on the inside, drill a hole and make a pen out of it.

If your blob is smaller than the sierra blanks, try the retro from woodcraft (a berea kit) for shorter tubes.

If it still looks like a blob on the inside, toss it as others have mentioned.

(yes, I have made blobs too.....)
 
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Let me explain the set up time confusion.

I stirred both colors back and forth for a while, they didn't seem to start to thicken up, so I left them alone for a couple mins... I came back to them and they were a molten mass in able to be poured.

Start to finish time of MEK was not two mins.
 
redneckmedic said:
Let me explain the set up time confusion.

I stirred both colors back and forth for a while, they didn't seem to start to thicken up, so I left them alone for a couple mins... I came back to them and they were a molten mass in able to be poured.

Start to finish time of MEK was not two mins.
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In my experience, PR seems to set up pretty quickly once it starts to go. I've had similar experiences where I've watched/stirred for 20 minutes, then left it alone for 2 only to have it gel up on me. There are so many variables at play - experience will help you figure these things out for your setup.

I also started with the Castin' Craft I bought locally... I've had much better luck using Silmar 41. Fresh resin does seem to make a difference!

I've had pours in 3/4" PVC take up to 3 days before they shrank enough to pop out of the mold. They'll be ok, it just may take a while longer! :)
 
redneckmedic said:
Let me explain the set up time confusion.

I stirred both colors back and forth for a while, they didn't seem to start to thicken up, so I left them alone for a couple mins... I came back to them and they were a molten mass in able to be poured.

Start to finish time of MEK was not two mins.
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I would use this as a learning experience. Did you heat the resin first? You said that you got the pr from michaels what is the date stamp on it? could be old pr also.

I will pour anywhere from 20 to 40 oz at a time. It can take several min for it to start to set. I will use 4 or 5 drops per ounce and have had it take 4 or 5 min to start to gel.
 
Hopefully your next attempt is MUCH better. Don't throw that one away though. You should see if you can shape it into a somewhat irregular, roundish (ball) shape. Once it does fully cure you can tell your kids it's an elephant booger....if you have boys, trust me, they'll fight over who gets to keep it. lol
 
I'm going to make one BIG suggestion.

FIND SOMEWHERE ELSE TO CAST!!!!!!


PR in the house is not a good idea. The fumes are not healthy.

Otherwise. Pour another color and cut it up. voids can be fixed later.

Keep trying.
 
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