Lessons Learned #1

Do not mix your resin in small cups. Give yourself room to stir or you may end up with an inadequate mix which will ruin your resin. This is especially important with fast setting resins like Alumilite.

20170421

Mixed 2 Tbsp (29 g) each of clear with glitter and pink(ish). Poured into four bangle molds, one of them not quite full. I had a difficult time pouring into the small molds without getting glop on the top of the mold, we’ll see how it comes out. After an hour under pressure I took them out but the mold was still flexible but the resin was not tacky so I decided to let them cure overnight. Tried to use mini pipette to get resin into mold, but the resin was heating up in my hand so I ended up pouring it in. I noticed some white areas on top of one mold, suspect either an incomplete mix or moisture contamination.

Result, fail. There’s a concave ring on top of each, maybe from shrinkage. I rough sanded the largest one to remove flashing. Once sanded i wiped with alcohol and it ruined the piece. Apparently it softened the surface so now it’s all cloudy. Not sure how to remedy groove in top where there isn’t a mold.

20170411

Today:

Tried a dye swirl in clear resin. Mixed 55 grams part A and B in same cup. Then poured into silicone mold. Placed one drop of blue Alumilite dye at one end of the mold. Using a cut down mixing stick, I dragged through the resin pulling lines of dye through the blank. I’m not sure it’ll cure right with a blob of dye not mixed in, but we’ll see. Poured extra resin on HDPE sheet to see what happens.

Upcoming:

Complete build of flat mold out of HDPE.

Challenges:

Use less dye

Update:

Blank did not cure correctly. After hour under pressure blank is very soft. Probably did not mix adequately. Where blob of dye was the blank didn’t solidify.

20170409

Today:

Used the vertical acrylic tubes. I washed the tubes and dried them in front of the heater. Sprayed with stoner from both ends of tubes and plugged with silicone stoppers. Tubes appeared uniformly hazy after spraying so I think they’re sufficiently coated.

I warmed the resin parts in front of the heater while the tubes dried. Part B was nice and thin like part A. Mixed 25 grams of part A & B for each color. This resulted in roughly two blanks, maybe a little short. I mixed color into “A” side. Concept is for a candy swirl blank; in this case strawberry:

White Pink
3 drops white dye 3 drops white
2 drops red
1 scoop Flamingo Pink Pearl Ex

Demolding was super easy, stoner urethane mold release was awesome. My first tube pour was unsuccessful, mainly due to the fact that I had to destroy the tubes to get the blanks out, which also broke. I’ll try a horizontal pour to get better swirls. Could use a little more resin too. These two blanks are 4 1/2 and 4 3/8 inches. Should be 5 1/4 to 6 inches.

Upcoming:

  • try pressure pot in horizontal position.

Challenges:

  • Need new sheet of HDPE
  • J-bolts might be able to hold pressure pot on wall

20170408

Today:

Threaded rod and bar mold clamping idea isn’t going to work in the HF pressure pot. I either need to use a vertical mold or a narrower mold. maybe three blanks at a time.

Upcoming:

Kristin suggested using the pressure pot on it’s side. I’ve seen Higgins use his pressure pot on the side but never considered it. that may be the ticket though. Need a stand for it and a board to make sure the inside is level.

Blockers:

need a good mold.

Resin Casting Pen Blanks – Second Try

Inspecting my second batch of blanks revealed that my mold is not square. The way I placed it on the board could have warped is a bit as the mold is too thin on the bottom. I’m going to try casting in the 1/2″ acrylic tubes i have. This time I’ll use Stoner mold release, which I didn’t have last time. I’m also going to rebuild my flat HDPE mold. I’m thinking that I can hold the mold together with threaded rod and square tube stock with wing nuts instead of screws. Hopefully this will result in a mold that’s easy to assemble/disassemble as well as square and leak free.

Coffee Inspired Resin Pen Blank

Today I’ll try for a coffee pen blank. I’m visualizing a dark brown blank with swirls of cream.

Setup:

I poured two sets of 55g each “A” & “B” this time. I added my colors to the part “A” component. One “A” part received five drops of Alumilite White. The other, five drops of Alumilite Brown and a small scoop of Antique Copper Pearl Ex.  I alternately poured each color into the mold. I started with white and poured along the blank’s axis in each cavity. After completing the pour I pressurized the pot for one hour. This time I made sure to level the board in the pressure pot.

Demold:

Coffee Pen blank
Demolded blank. You can clearly see where the mold contained small bubbles in the silicone.
Coffee Pen Blank
Looks more like Root Beer Float

There was no problem removing the pen blank from the mold. My previous pen blanks were still flexible after I removed them from the mold. To find a solution I looked at the Alumilite FAQ. The manufacturer recommends post curing. I found the information on the Casting tab, under the question “It has been 4 hours and my clear resin is still flexible, will it harden?“. Following their advice, I allowed the blank to cure in the toaster oven at 160 degrees for an additional two hours. This resulted in a blank with zero flex when trying to bend it by hand.

Observations:

My coffee pen blank turned out more like a root beer float.

I should have mixed 110 g of resin total, instead of 110 g of each color. Since I mixed so much, half of the resin hardened in the cup. I didn’t have an additional mold ready to pour the excess into.

Pouring white resin into brown does not result in a mocha like color swirl. I’ll have to mix brown and white to make a more beige color.  I’ve learned that the colored resins don’t mix without agitating them.

Resin Pen Blank, First Attempt

This is my first attempt and creating a resin pen blank. Samara helped with the concept for these pen blanks. She wanted to combine gold for her and orange for Asher.

Setup:

I mixed 51 grams of each “A” & “B” part of Amazing Clear Cast resin. We added three drops of Alumilite Orange dye and one scoop Solar Gold Pearl Ex powder to the “A” side of the resin before mixing with part “B”. 102 grams of resin was not enough to fill both cavities of the mold that I made.

First pen blank
First pen blank

Demold:

The pen blanks came out of the mold easily although I could tell immediately that they were not quite what I expected. I’m encouraged by the look of the top surface. Once polished it might make a nice pen. The side of the blank is rough however, showing little bumps where there were surface bubbles in the mold. I decided to round out one to see what a pen might look like. The resin still needed days to cure and I found that there was significant flex in the resin. I could actually bend the blanks by hand. This pour drove home the lesson that demold time is not the same as cure time. I knew the pen blanks would need to cure but had thought the resin would be harder after the demold time elapsed.

Observations:

I did not level the board holding the mold in the pressure pot and one end of the pen blank ended up 3/4″ while the other is only 1/2″. Since I was unable to degas the silicone, the mold has tiny bubbles along sides. I made the mold out of Alumilite High Strength 3 which should have set without bubbles. I think air must have clung to the HDPE blocks I used to form the blank cavities. The bottom of the mold lacks dimensional stability. Being maybe a 1/4″ thick the blanks cast in it tend to have a slight curve on the bottom, conforming to whatever it’s sitting on.