color of poured resin,,

[stevers]

Hi All,
Real quick question,
What color is freshly mixed PR? I bought Bondo brand (just what Walyworld had, only doing a test cast) and it mixed sort of a maple syrup color. Is this normal? Also, I used 50 drops for 10 onces, sound OK??

Thanks in adv.

 

[its_virgil]

If you are wanting clear, it should be clear. I'm not sure about the PR that wallmart sells...I purchase water clear for both clear and tinted. It may cure clear. I use 3 drops of MEKP per ounce.
Do a good turn daily!
Don

Originally posted by stevers
<br />Hi All,
Real quick question,
What color is freshly mixed PR? I bought Bondo brand (just what Walyworld had, only doing a test cast) and it mixed sort of a maple syrup color. Is this normal? Also, I used 50 drops for 10 onces, sound OK??

Thanks in adv.

 

[stevers]

Thanks Virgil,
Thought I had heard someone say the PR they use started out Smokey. I'm hoping that anyway.

 

[OKLAHOMAN]

I also use clear PR and tint to desired color except for most cactus and all snake. The PR should say on the container "clear casting resin". As Don said don't know what Wally world sells and if it would cure clear.

 

[gketell]

The Michael's stuff starts out slightly amber but dries nearly clear. After finishing off that quart I just ordered a gallon of "water clear" from mrfiberglass.com.

GK

 

[stevers]

The resin is still pretty smokey. I think the stuff I grabbed is not a clear type. It was just for experiments sake anyway. It is actually Bondo brand, you know like the bondo you used to use to fix the body of your car, only its their fiberglass resin. It's polyester resin, it's just not clear. I may turn it anyway, just for fun. And so my first cast will have a memento.
I'll go to Marge's Hobbies tomorrow and get some clear casting resin. She has Castin'craft brand. I was just trying to save a few bucks on my experimental first cast. The Bondo stuff was only $10.50 for the quart and she wants $15.00 a pint and $25.00 a quart. Not to mention $90.00 a gallon. I will deff go to the net for the first gallon.

 

[stevers]

Boy did I screw this one up. I have to do some research, but all indicators point to this being the completely wrong type of resin.
**It was smokey when mixed,
**It dried within 2 hours,
**It is flexible like stiff rubber,
**It cracked across the bottom of the cast,
**with 30 minutes of vacuum and 2 hours of pressure it is still filled with air bubbles,

That was a good lesson learned on that one. "Buy the right s_ _t!"
I put in some photos bellow, I know some of you will want to see how bad this one went wrong,

this is the stuff I bought at Wallyworld,

<br />

these next three are the block I cast. I cut one end off to get a better look inside. That is cactus impregnated in it, luckily I have a lot more.

<br />

<br />

<br />

OK, now lets hear it folks, I deserve it for being in a hurry and worrying to much about a couple of bucks. Now it cost me a 10 and a half dollar can of resin.

 

[Glass Scratcher]

Originally posted by stevers<br />
I'll go to Marge's Hobbies tomorrow and get some clear casting resin. She has Castin'craft brand. I was just trying to save a few bucks on my experimental first cast. The Bondo stuff was only $10.50 for the quart and she wants $15.00 a pint and $25.00 a quart. Not to mention $90.00 a gallon. I will deff go to the net for the first gallon.

I was going to point you to your local surboard repair shop, but I don't think you have any close by.[8D]

You may want to check with your local or regional auto body/paint supply depot to see if they carry any Silmar 41 type product. Just remember to get the stuff without the wax added.

 

[PenWorks]

Steve, the picture of the Boat and car on the can should have been a clue []
Another good lesson learned, nothing like the school of hard knox. []

 

[stevers]

Anthony,
I thought fiberglass resin was polyester resin?? Also, I found out this stuff is 60 to 70% resin and 30 to 40% styrene. Is that wrong also??

 

[fiferb]

If anything you learned what not to use. Thanks for sharing your experience.

 

[BRobbins629]

And you thought this is easy? (it really is once you get a few right) All PR resin has styrene whether for fiberglass or pens. That's actually the part that stinks. You need the styrene to make it pourable. For fiberglass shops, they even sell styrene by itself to add as a thinner.

I would try at least one pour without cactus and make sure that is not causing the bubbles. Could be it isn't dry. As long as you have the resin, I would keep trying with it. 2 hours isn't much time to cure.

 

[stevers]

Youbetcha Bruce F.
Bruce R. Actually I did cast a piece with some old dry wood in it. Had an ounce or so left in the measuring cup so I poured it in a little plastic container. Lot of bubbles, not as many, but way to many. Also the resin still hasn't fully hardened. It is still kinda soft. I can stick a screw driver right into it. Wrong smell too. I'll get the right resin and it'll all be ok.

 

[OKLAHOMAN]

Steve,

Just make sure when you buy resin next time that it's clear casting resin and Bruce is right about the cactus it will cause bubbles if its not completley dry DAMHIKT, go ahead and use what you have to "play" with. If you have some India ink you might add some to color the resin.I've been buying 5 gal at a time from composite one @ about $160.00, you might want to check to see if you have a composite one in your neck of the woods. If so PM me and I'll PM you back the product info.

 

[stevers]

Thanks Roy,
I still haven't decided where I'm going to go for resin. I've had several good suggestions from folks. 5 gals and $160 is more than I could get by the wife. Appreciate the info, let you know if I think about going your way. Leaning toward this right now,,,,,,,,,,,,,,,
http://www.artstuf.com/DStockNEW.fm$RETRIEVE?sortcode=PR032369&html=display

 

[gketell]

One thing to keep in mind is that you want to switch from vacuum to pressure while the resin is still liquid. Vacuum will cause the air bubbles to increase in size, hopefully to the point that they float out and/or pop. But if not, you don't want them being held artificially big while the resin sets. Then the pressure does nothing for you.

I would vacuum it once or twice (vacuum/release/vacuum) in a five minute period (for normal casting resin) and then switch to pressure to reduce the size of the bubbles as much as possible before the resin starts jelling. If you use Alumilite you have to do all that in less than a minute because you only have 3 minutes until it jells and 10 until it is done. (Or something fast like that. I haven't used it yet due to fear of being too slow (plus there is no place close to get it.))

GK

 

[stevers]

Originally posted by gketell
<br />One thing to keep in mind is that you want to switch from vacuum to pressure while the resin is still liquid. Vacuum will cause the air bubbles to increase in size, hopefully to the point that they float out and/or pop. But if not, you don't want them being held artificially big while the resin sets. Then the pressure does nothing for you.

GK

Greg,
I believe that is exactly what happened. It set so quickly, it suspended the bubbles in the resin. It was setting up after less then 15 minutes and set firm in somewhere around 30 minutes. I pulled vac for 20, then went to pressure. I was way too late.
Like I said earlier, this is the "wrong" product. It is still spongy. Like a hard rubber ball. It apeares to be a resin used for repairs around the house or garage.
I'm not going to waist any more time with it. I'll pick up some "Castin'crafts", clear casting resin Monday and do it right.

 

[MesquiteMan]

For cactus casting I would not use vacuum at all unless you just use it to de-gass the resin before you pour. Cactus skeletons cause a lot of little air pockets in the resin. Vacuum will cause the air in those pockets to expand until it spills out but the air pocket is still the same physical size. If you use pressure, it will reduce the size of the air pocket to where it is hopefully invisible.

In my experience, vacuum does fine for de-gassing and for solid resin with nothing embedded but as soon as you put something in there that has the potential for air pockets, pressure is preferred. I use 60 psi for this very reason. I want those air pockets as small as possible.

Also, I can't post in a thread like this without mentioning that if you use Alumilite you will not have to worry about the smell or the number of drops or the fact that styrene is REAL bad for you![xx(][:0][] (Then again, as Don Ward will surely say, you will not have any money left either!![][])

 

[gketell]

I'd say get a qt of castin crafts to play with and then order a gallon of the mrfiberglass resin at the same time. Why? 1) the qt of castin craft I bought made only 8 (7.5 really) pen blanks, 2) I ordered the mrfiberglass resin on July 5th and it is still not here so the lead time is easily longer than your qt will last.

MrFiberglass also has lots of tutorial/faqs/etc to help you along.

GK

 

[gketell]

Curtis,

With the speed of Alumilite, do you have time to degass the resin, pour, seal the pot then get 60psi of pressure before it is already setting?

I really like all the upsides offered by alumilite but that setting speed scares this newbie.

GK

 

[stevers]

Curtis, thanks for the info. It will be very helpfully. I hadn't gotten any answerers on casting cactus. You brought up things I did not know. Thats probably why there was so many bubbles in the first block. The second one had some too though. And it had only a couple of pieces of dried wood in it. But they could have caused some bubbles too I suppose. Boy, this is harder than I thought. Greg was right.

And Greg, that's just what I planned to do. That way I can play some more and hopefully get the hang of this before I go broke waisting resin. Did you already give me the URL for Mr.Fiberglass?

 

[stevers]

Greg, found the site, which one do you use?

never mind, I found it.

 

[its_virgil]

Why couldn't you degass both parts of alumilite before mixing them together. Then mix and add colorant.

On polyester resin I use 3 drops of MEKP per ounce, mix in the catalyst, degass for 8 minutes, then pour into the mold and place in the pressure tank.

BUT, I've started using ultrasonics to degass PR (a la Bruce Robbins). It is sooooo much easier than using vacuum and as far as I can tell it works just as well. I've done two separate castings and all is going well. I will continue to use ultrasoncis as long as the results are satisfactory. Thanks Bruce. Be aware, I only do snake skins...I don't do very much of the colored resin...in fact hardly any at all.

Listen to Curtis if Alumilite information (and empty pockets [][]) is needed. Curtis knows alumalite!!

Happy casting and ...
Do a good turn daily!
Don

Originally posted by gketell
<br />Curtis,

With the speed of Alumilite, do you have time to degass the resin, pour, seal the pot then get 60psi of pressure before it is already setting?

I really like all the upsides offered by alumilite but that setting speed scares this newbie.

GK

 

[MesquiteMan]

Greg,

I do not worry about degassing Alumilite. I have not found a need in the hundreds of cactus blanks that I have cast. When I used to have significant bubble problems it was because the skeletons were not 100% dry. I have a good process now to eliminate that problem.

I routinely mix and pour 20 ounces of mixed Alumilite at a time and have not had any issues AT ALL with the stuff going off before I was ready. I have plenty of time to mix the resin thoroughly, pour into my molds, put into my pot, and pressure to 60 psi. And I do not rush at all. When I first started I sure was nervous though!

Give Mike at Alumilite a shout and ask him for a sample. He will surely send you one if you mention you are a member here. Then you can see for yourself!

 

[gketell]

Thanks for all the info Curtis! Again!!
I love this board and all the great people on it!!!

GK

 

[neon007]

Here is a link to where I get my poly resin. $30 a gal. http://www.shopmaninc.com/polyesters.html Scroll down till ya see silmar 41 clear casting resin. hope this helps

 

[stevers]

Thanks Keith,
I went ahead and ordered from Mr Fiberglass a couple days ago. He matched that price. Actually gave it to me for $30.94. Works for me. I just chose to go with Mr.F because of some comments and info I heard. No knock on US Comp. I'm sure they are just fine as well. Just how I wound up going.
Thanks for the sug.