Boiler capacity

Hi,
Im looking for advice on how much water treatment to add to my 4"agricultural, and how often
I need to figure out how much water the boiler holds. ?

A previous posting back in March 2011 has it at 27.8 litres.
as for treatment requirements that depends on water quality and usage.
I have seen a write up on the heritage steam web site under boiler water treatment may be worth a read.
They also sell a kit for testing the water, the cost of the kit is high but the cost of a new boiler will be horrific I think.
Simon

Thanks simon. I had guessed 30 ltrs.
Looks like I'll need an initial dose in the boiler of 100ml.
Then occasionally 10ml thereafter.

I was speaking to Lynnr last week and her advice was no boiler treatment for the first several (10) steaming's with a full blow down of the boiler for these First steaming's. this is to help clear the boiler of the nastiest left from manufacturing of your boiler, and prevent purging.
Simon

Yes , thats one job this weekend.. at least a few more steamings before I use it then. 😏

I was advised that on a new boiler not to put treatment in for about three months to allow a light coating of rust to form. Then apply treatment as the rust gives the treatment something to stick too. Regarding how much, I put a small cup full in at the beginning of the season and top up as required. To check the strength I use litmus paper, it should be around 10 which is dark blue on the litmus paper. I bought a reel of it on eBay for not much (less than £2) and tear off an inch & hold it under the blowdown valve when slightly open. Unless you prime a lot or have your safeties blasting away the strength doesn't vary much as the steam the engine is using is pure water. Regarding blowing down, I don't do it, I understand the value of it if you are sucking up water from a river but clean water from a tap I just don't see the point and one is just blasting treatment into the ground. I accept there are strong views on this and am still open to persuasion that it has some value on clean water.
I have run the agricultural for 11 years now and each Autumn I wash out the boiler until the water runs clear from the treatment and there has never been any grit, mud or sludge to deal with.

Thanks steve. Today im going to wash out the boiler as its new and only steamed twice.Then i can leave it full,ready for next steam up.
I had drain off cocks blocked last week.so i may have manufactured debris to clear.

I always recommend that with a new boiler before you paint it stand it on its end with the wash out plugs on the ground and give it a good beating with a softwood stick to shake loose all the swarf that is stuck inside the boiler with the cutting oil. Then fish it out with a telescopic magnet, you'll be surprised how much comes out (about half a cup full). It save 12 - 18 months of blocked clacks and gauge glass blockages. Eventually it all rusts away to nothing so long term there isn't a problem. Washing it out with a pressure washer removes some but where you can't get it still stays there so hitting it with a stick when it's all dry inside gets more swarf out.

The 27 litres spoken of is the boiler capacity when filled to the brim. That is the capacity which is a question raised during boiler inspection for your steam certificate.  
However the typical amount of water in the boiler during steaming (half way up the gauge glass) is about 20 litres.
I use Multitreat available from Heritage Steam Supplies (other sources available I'm sure). Their datasheet recommends 3000ppm dosage.
If you do the maths this works out at 60ml for the 20 litre steaming water level.

Chris