5 replies to this topic

[Sparky]

Hi all

When making some comps with water and AL that need Boric Acid is there an easier way to get a water / boric acid solution made up before for the mixing? Most comps I see measure it out by weight and then you have to be very precise about getting the right amount of water with it dissolve din first.

I was thinking that I could simply make up a spray bottle first that I use for the purpose. What concentration would be good for this? If it is a good idea at all?

[bangkokpyro]

I always add the percentage of Boric in the formula to the other chemicals and screen them together before wetting but I suppose you could dissolve it first in a small amount of water, add it to the comp then add more water until you have the right consistancy for cutting/pumping.
If you were going to roll stars with Nitrate /fine Aluminium content you could put it into a spray bottle, I would think a 5 % solution would be sufficient to prevent unwanted reactions.

[dave]

if its any use heres the solubilty

2.52 g/100 mL (0 °C)
4.72 g/100 mL (20 °C)
5.7 g/100 mL (25 °C)
19.10 g/100 mL (80 °C)
27.53 g/100 mL (100 °C

ive always thought it much better to add as a solution since in theory this should give a more uniform disribution in the mixture

dave

[dr thrust]

some people prefer to add boric acid directly, some in solution its all about personal preferences, i myself add it as a solution at 2%, which in my thinking is 2 grams of acid to 100g of water, as volume of water = 100g / 0.9957 g/mL
= 100.43 mL of water or near enough for me
one tool i have found indispensable, for this sort of thing is the humble glass measuring cylinder ( ebay) also great for measuring out solvents in whistle mixes.

[Mumbles]

I've had better luck in preventing reactions when using it as a solution. I tend not to use it all that often anymore unless I feel like it is prone to having an adverse reaction.

[Sparky]

Thanks guys, great advice as usual.