I made some samples of the waterweld, which is a putty type substance that quickly goes hard after mixing. I left them in the different cleaning chemicals I tend to use and have to hand - for 24hrs then rinsed and dried. These are the results:
Cheers
- There was no visible change to the ones in:
- Caustic Soda/sodium hydroxide (the drain-cleaning stuff) at 20g/litre
- 2x Sodium Percarbonate to 1x Sodium Metasilicate cleaner, at 5g/L
- There was almost no change but perhaps 'minimal' surface roughening to those in:
- Starsan (at recommended no-rinse dosage)
- Peracetic acid at 0.1% solution (or 20ml of 5% strength acid per litre)
- Phosphoric acid at 1% solution (or 12.5ml of 81% strength acid per litre)
(As an aside, I used sharpie markers to label the sample pieces; the bleach completey removed the ink, the peracetic acid largely removed it, the percarbonate cleaner had some effect and also to a lesser degree did the starsan. The phosphoric and caustic had no noticable effect)
- There was noticable surface degredation to the one in:
- 'Very' Strong Bleach - 2.5% w/w sodium hypochlorite (neat Dettol mould and mildew remover)
(though thats a very strong solution for bleach - I typically only use it as a short contact time spray cleaner)
So not an especially rigorous or scientific trial but the results serve their purpose. In most cases 24hrs would represent the cumulative contact time from a considerable number of brew days; the only one I normally leave for extended periods is the percarbonate-based cleaner, though the starsan and peracetic acid sanitisers could hang around if they collected in puddles on the waterweld, as they're normally used as no-rinse sanitisers.
Kev