Soda ash in fabric dyeing


In The Industry
Mar 29, 2007
Knippa, Texas
This is related to chemicals USED in a pool, but I had a non-pool-use question!

Soda ash (sodium carbonate) is required for dyeing fabrics with certain types of dye. The site where I buy my dyes has something called DENSE sodium carbonate. I sent them a query asking how theirs was different from washing soda. I received a response but it wasn't very informative.

The "dense" sodium carbonate is somewhat more expensive than washing soda, but not vastly so. I am primarily just curious about it. Is it really different?
regular washing soda is in the dihydrate form. The means that every molecule of sodium carbonate had two water molecuels attached. DENSE sodium carbonate is the anhydrous form.
Anhydrous means 'without water'
This means that on a weight for weight basis the anydrous form will make a more concentrated solution but if the different molecular weights are taken into account there is no difference in use.
This is very simialr to the borate products based on sodium tetraborate pentahydrate (5 water molecules chemially attached) and 20 mule team (sodium tetraborate decahydrate with 10 water molecules chemically attached0. Either one can be used to raise your pool to 50 ppm borates but the 20 mule team will take slightly more by weight to achieve that 50 ppm result than the pentahydrate produdts like Optimizer or Supreme. The end result is, however, identical.