DH is ironing his work shirts and wants to know..

[Actors]

How you get rid of/avoid the armpits turning cardboard like? He thinks it's an accumulation of sweat and deodorant that doesn't come out in the wash. They don't smell though, he sprayed them with vinegar before washing

hot wash, and better deodorant
this is a fiver but you'll save on new shirts.

It is a reaction between sweat and the aluminium salts found in many deodorants. So to prevent it, buy a deodorant without aluminium (usually the wholesome-type ones). With several washes, it does eventually come out but I think if you scrub at it with a baking soda paste it will help.

I would also wash them on 90C with bio detergent and hang them out in the sun next time.

Thank you - I like the sunshine advice. It's great that he does laundry, but it is a source of constant "discussion" that he refuses to use the washing line as the tumble dryer makes ironing easier.

Get them nearly dry on the line and then do 20 minutes on a low heat to smooth out wrinkles?

Napisan - if crust has formed then mix Napisan to a paste and spread on, leave for 12 hours, then wash on 60' with Daz and Napisan.

After, just always wash with bio washing powder and add napisan and it won't form again.

baking powder works a treat work in before throwing in the wash if bad.

Warm some cheap vinegar in a pan, you dont have to but it helps if its warm, pre-treat the underarms and leave for 10 minutes.

Wash as usual.

I've rescued tops with this.