Hydrospan

'Chic McGregor' wrote dimensions possibly. However it looks like it might at least be a useful rough scale up.

I think this was discussed a few months ago, and Chris Pardell ordered some and gave a blow by blow evaluation. Go to the newsgroup 'archiver' at google.com, search for alt.sculpt, and then a search for Industrial Polymers. I have their great catalog, but have not had a chance to order yet. Still working in clay squeeze molds, plaster piece molds and waiting to try gelatine molding - born in the wrong century I guess! Ok - I make resin piece molds too.

Yeah- I used the hydrospan.

It works pretty well on smaller items, and particualarly well on items that have a lot of surface area for their volume.

However- the closer an item is to spherical- like say a human head- the longer it takes to expand to its full size- I had a head about 3.5 inches in diameter and it took nearly 3 weeks to attain full expansion. Also- in large volume to surface castings it is particulalry sensitive to being mixed perfectly- very small variations in mixture consistency result in large scale flaws.

The pity is that you are stuck with the full expansion of the product- Until the product is fully saturated with water it shows significant distortion. Both warpage and 'cellulite'-like lack of fairness.

The same company makes a material that is supposed to do the opposite trick- that is, SHRINK significantly- but the sample I have tested shows that it does not work at all for sculptural purposes.

Good luck with the hydrospan, Chic

[That's an alginate that shrinks as it dries. I tried it, was unimpressed.]

Andrew Werby