Caustic soda update

[ex-Gladys]

As promised... Slapped 250g in 1litre water + 50g wallpaper paste on one side of the keel Sat. Not really a good day to do it with the low temps. It didn't "fall off" as with Dilunett, but with a wallpaper scraper got back to the epoxy more readily than the other side.

Wife says from her days as an industrial chemist that it's because the stuff we're buying from B&Q is hydrated sodium hydroxide rahter than "neat". We're (sorry, She's) going to try a whole small pot (500g) next weekend and wathc the effect.

Overall it does leave the remaining antifoul and primer very soft, and it does appear to come off more easily.

Watch this space for next week's exciting instalment.....

 

[Trevor_swfyc]

As an industrial Chemist no doubt your wife will have informed you of the dangers of slapping caustic soda into water, indeed it concerns me that if somebody followed your advice they may not be in a position to read next weeks's exciting instalment!

Stay Safe!

Trevor

 

[VicS]

[ QUOTE ]
the stuff we're buying from B&Q is hydrated sodium hydroxide rahter than "neat".

[/ QUOTE ]
Please explain. I've obviously missed something. I've only ever come across pellets, pearl or solutions

 

[JimMcMillan]

you can add caustic to water without much danger but NOT water to caustic

 

[ex-Gladys]

The pellets are not necessarily 100% NaOH apparently. If you ask a pharmacy, theyare not allowed to sell pure NaOH any more, so by deduction the stuff in B&Q won't be pure. Going on the comparison with Dilunett, and the effects seen so far, I would believe it, since it looks like we will need to use close to 500 g per litre to achieve the Dilunett results....

 

[Birdseye]

any signs of the caustic affecting the substrate?

 

[ex-Gladys]

Absolutely none. It's gelshielded, and caustic soda doesn't affect two pack paints.