Does anyone know where I can buy some washing soda crystals..?

It will be used for natural washing powder for clothes.

I have never been able to buy them in Thailand and the reason I think you have had no replies is that no one else has either.

Unless of course any of you know better?

Would be interesting to find out why they are not available. Everything else seems to be, except for Monster Munch.

Washing Soda (chemical name: Sodium Carbonate) is available in Chiang Mai. I have purchased it at a chemical supply store located on the road the runs past the chang puak gate. The road inside the gate (to the south of the gate). It's located about 200 meters past the gate. At the chemical supply store it's not cheap (I've forgotten the price) because it is highly purified.

You might also try a pool & spa supply store. Sodium Carbonate should be on sale there. It's used to raise the PH of the water. Should cost a lot less there.

there is a few chemical shop in chianmai which i offen go to buy so i can have fun making lal kinda weird mix up ,

try world chemical - along the high way just about 200-300meter after the chiangmai land highway exit .

if you need a map pm me .

not sure if there have a number . one o fthe lady boss can speak english if i recall or is it another shop whhahahahhahaha

nice one guys, do you know what the name in Thai is or perhaps how much they normally cost....?

for less purity it's cheap stuff.

Also known as Soda Ash

Has lots of applications for cleaning equipment and foundry etc. . Used most commonly as a water softener. Also used a lot for food preparation like Ramen Noodles.

I would try the chemical place on Suthep road near Wat Suan Dok(south side of road). This place is lower purity and large quantities. They have a lot large white bags stacked up.