| Purpose |
Alginate |
Water |
Water temp |
0:00 ... 1:00 |
1:00 ... 2:00 |
2:00 ... 3:00 |
3:00 ... 4:00 |
4:00 ... 5:00 |
5:00 ... 6:00 |
6:00 ... 15:00 |
15:00 ... 45:00 |
Overnight |
| Initial experiment to qualify D&S alginate at same ratio as Pink House (6:1) |
25g |
150g |
30 C |
Mix by hand |
Mix by hand |
Inspect; very runny |
Vacuum |
Vacuum; could not degas, as 20oz cup was not big enough to contain foam. |
Stir; examine consistency. Runny, with a bit of body; like tomato sauce. |
Set against pouring, but jiggles significantly; then...
Set; very little jiggling, then...
Firmly set, but too soft to be useful.
| Set, just firm enough to be acceptable |
Set; significant excluded water. Soft, with good grain. Probably
marginal at taking good detail. |
| Second experiment; doubling mass ratio to 3:1 to get to a thick enough
consistency to do a good face casting. Using less of each to
try to allow degassing. |
40g |
120g |
30 C |
Mix by hand |
Mix by hand |
Very stiff paste; If it were beaten egg whites, it'd be at soft peaks. |
Vacuum |
Vacuum. At end of vacuuming, alginate has already set, leaving it set up in foamed form. |
|
Very firm; nearly dry to the touch. No un-foamed portion in
bottom of cup to check for strength, but foam is rather crumbly. |
No real change; nearly dry on top, wet when broken up. |
| Third experiment; splitting difference of 1st two at 4.5:1 water:alginate |
30g |
135g |
30 C |
Mix by hand |
Mix by hand |
Flows, runnier than stirred yogurt. |
Vacuum |
Vacuum |
After vacuum, has set a bit, and now is about at yogurty consistency.
Over the course of this minute, sets more, from ribbon/soft peaks
to definite soft peaks. |
From soft peaks to set very quickly. A bit too fast to be useful, IMHO. |
Nice and firm. In same league with Pink House, but I think, not
quite as solid. |
Set. Good grain, very little water excluded. As firm as Pink House |
| Hand mold to check quality of detail capture; bumping the ratio
a bit up from the too-thin of 6:1 to 5.25:1 water/alginate by mass.
Pose is a peace sign, with thumb curled over ring & pinky |
286g |
1500g |
30 C |
Mechanical mixing |
Mechanical mixing |
Vacuum |
Vacuum - pours readily into mold |
Very foamy under vacuum; had to admit air 3 times to bring bubbles
down before last of air was gone and boiling commenced. |
Went from quite fluid to almost-set within under 1 min.
Wet hand and left to get a towel. By the time I got back, alginate
started to be grainy and almost set. Got hand posed, and less than
1 min. later, no flow at all. |
|
|
Inverted overnight to allow excluded water to drain. |
| Hand mold to provide control vs. Pink House.
Mixed at standard 6:1 for PH Alginate.
Pose is a peace sign, with thumb curled over ring & pinky |
250g |
1500g |
30 C |
Mechanical mixing |
Mechanical mixing |
Vacuum |
Vacuum - pours into mold, but manual removal of last bit is necessary due to viscosity |
Foamed and fell nicely under vacuum; did not need to pause pump
or admit air (but only just barely). This may be due to greater
viscosity holding bubbles more poorly. |
Takes quite a while to set, almost annoyingly long for a hand mold. |
|
Pink House is very much stiffer than the Doulgas & Sturgess alginate;
the D&S deformed a bit when I squished it - probably not enough to
warp the resulting cast noticeably, but maybe. |
Inverted overnight to allow excluded water to drain. |