Have You Tried Mixing Hair In With Your Plaster Or Water Putty Molds?

[Chuck Young]

I was having a little trouble with water putty molds and fragility. Then I remembered the horse hair plaster in my mom's house. I have a cat that sheds like a .. well, like a long haired cat. I saved the stuff that comes out of the brush. after applying a thin coat of pure putty on the lure, I mixed the hair in and applied the rest. It seemed to help a little. I'm sure epoxy will strengthen even more. Just wondering if anyone else has tried this and what your results have been? BTW if you need pet hair and are willing to pay shipping.....

[Bogbaits]

I dont do hair but all my water putty molds get coated on the outside with 2 ton epoxy and then wood slats applied to the outside over the epoxy,if they should ever crack they will not fall apart,it keeps them together,I have had the same molds for over 10 years using this process

[mark poulson]

I use strips of fiberglass drywall tape laid into my mold boxes before I add the pop, and lately I've been adding carpenter's yellow glue to the pop mix.  It makes the mix hard, so it holds details really well.

[JRammit]

I used dryer sheets for a while... They helped hold the mold together if i got small cracks... But the sheets couldnt support bigger cracks

Now i just make my molds thicker... Plaster is cheap, more is stronger.... Each mold half is > 1" thick... Only had one break since, and that was because i tried to build an injector into the plaster

But remember, 2x thicker = 2x dry time

Edited June 16, 2016 by JRammit

[JRammit]

I use strips of fiberglass drywall tape laid into my mold boxes before I add the pop, and lately I've been adding carpenter's yellow glue to the pop mix. It makes the mix hard, so it holds details really well.

Mark, does the glue give you any problem with bubbles?

I tried this the other day, but i mixed the glue into the water before adding the plaster.... Mixed until it looked like a bubble bath, then decided to throw it away

Im guessing you mix the plaster 1st, THEN add the glue

[mark poulson]

Mark, does the glue give you any problem with bubbles?

I tried this the other day, but i mixed the glue into the water before adding the plaster.... Mixed until it looked like a bubble bath, then decided to throw it away

Im guessing you mix the plaster 1st, THEN add the glue

I mix the pop and then stir in the glue.  I haven't had any problem with bubbles from the glue, so far.

I let it sit for a couple of minutes once it's mixed, and shake/vibrate it, to help any bubbles come to the top.

I only make two part molds, from 1/4" plywood and 1X borders.  I use cut off 8D nails in matching holes to align the two halves

Once I pour it into the first mold box half (3/4" thick because the box border is 3/4"X3/4"), I vibrate it again, let it sit a minute, and then add my masters. 

Once the first half has set and been oven dried at 170 for an hour, I seal it with D2T that's thinned with DA.

The next day, once the epoxy has completely set, I repeat the process with the second mold box half.

I spray the face of the first half with Pam, wipe it off of the masters, and use an acid brush to coat the masters with fresh pop from the second mold box half.  

Finally, I put the first half face down on top of the second half, clamp the perimeter all the way around, and then flip it over, so the wet pop is on top.

I tap the mold hard with a rubber screwdriver handle, and the put a palm sander on top of the sandwich for 30 seconds, just to try and get any air bubbles to migrate up away from the first half.

I follow the same drying and sealing program with the second half after it's set and I've pried it apart.

If I've done it right, the two halves come apart cleanly, and there is minimal trimming and cleanup.

For me, the hardest part is getting the right amount of pop into the second half, without lots of squeeze out and overflow.

I've found that underfilling slightly is way better than overfilling.

I hope this is clear, and helps.

Edited June 16, 2016 by mark poulson

[SlowFISH]

I use strips of fiberglass drywall tape laid into my mold boxes before I add the pop, and lately I've been adding carpenter's yellow glue to the pop mix.  It makes the mix hard, so it holds details really well.

 

I don't use drywall tape (but I like that idea!!) but instead use wire mesh which adds a good amount of rigidity... I form/fold it to "stand off" the part - clip it as needed to create a couple legs then pour.

 

Also - there are other plasters that are "harder/stiffer" if you look on sites that sell sculpting supplies.  At one point I was using Ultra Cal l to get a decent mix of rigidity and detail... but I felt standard POP gave a smoother finish so.... I'd mix both - pour a thin layer of standard POP and brush it over the part - then back fill that with the Ultra Cal and let them dry together.  Seemed to work well.

 

  J.

[Chuck Young]

Great posts guys! Mark, I really like the palm sander vibrator.

[Bogbaits]

I dont believe dryer sheets or fiberglass sheets will support any large cracks that why I use wood strips one half inch thick,2 inches wide  and they run the full length of the mold and are epoxied to the outside of the mold,I run a lure making buisiness and these molds are used daily for over ten years,i have done the mesh thing when pouring the molds but it wont help you when you drop the mold,it falls and cracks,you need to stiffen it up on the outside,have had them crack from falling but it never effected the mold!!!You could even go one step further and epoxt wood strips on the sides of the molds also for a bullet proof mold,I never ever had to though!!!

[mark poulson]

I dont believe dryer sheets or fiberglass sheets will support any large cracks that why I use wood strips one half inch thick,2 inches wide  and they run the full length of the mold and are epoxied to the outside of the mold,I run a lure making buisiness and these molds are used daily for over ten years,i have done the mesh thing when pouring the molds but it wont help you when you drop the mold,it falls and cracks,you need to stiffen it up on the outside,have had them crack from falling but it never effected the mold!!!You could even go one step further and epoxt wood strips on the sides of the molds also for a bullet proof mold,I never ever had to though!!!

 

That's why I use wood boxes for my molds.  3/4"x 3/4" borders, and 1/4" plywood bottoms.  I still try not to drop my molds.  Hahaha

[Roger Linnell]

http://www.sculpturesupply.com/detail.php?id=220195&sf=subcategory&vl=Tuf+Stone&cat=Plaster+%26+Gypsum+Cement I've been using this stuff for quite a while, I think it's the hardest plaster known to man, I still glue a wooden frame around it