Plastering a wall, Any Guide out there on how to do it?

Ok guys wtf did just happened... Mixed up my first batch of plaster, not much maybe 6-7litres in a bucket, mixed it up to nice spreadable consistence in all sterile containers with cold water, and went off to put on a wall, did about half a square metre and was surprised how easy it lays on/spreads etc and leaves ok finish.. But than boom.. all of a sudden the mix started to harden on my trowel to rock hard, was wondering wtf.. the applied stuff on a wall became unusable.. went to my bucket and what would you know it also had started to turn rock solid hard, all happened within 4-5minutes after mixing it up.. mixed it up with a cold water in a consistence that it should probably be, but out of sudden it started to become very warm and within 10minutes in bucket its now rock solid hard that I can't even get it out of bucket anymore, will have to go and buy a new bucket.. third of a wall is a mess with hardened **** on it. and I have bucket full of solid warm rock..


What did I do wrong that such a reaction happened?

 

ok just checked that my bag was almost 4 months out of date, I had 1 full unopened bag that I had bought in past and wanted to use up first.
could It happened because it was out of date?

what's the usual shelf life of a plaster? I see that the plaster I bought yday is still 3months In date, seems really little timeframe since I got it from a freshly delivered plaster at b&q, or at least I think so..

 

after doing more digging, the plaster seems like indeed has only around 3 months of shelf life, mine was probably 3x older than that.
oh well..half a day wasted and whole lots of swear words used.. off to get another bucket

what do I do with the plaster that's already on the wall? try to scrape it off? it's already rock hard and close to impossible to get off without heavily damaging the plasterboard itself.

 

well put on first 2 coats on a ''learning'' wall, and my 2nd coat came out as the 1st coat should come out waiting to dry up a bit to do the final stage.

I now realized what's the difference between the cheap £7 trowels and the much more expensive ones.. Wear/grip on them. It's almost impossible to hold anything on that clunker without it sliding right off, same goes for the cheapo £9 hawk, but not as bad for the trowel. I did look at the more expensive trowels in shop as well and had a look at 10different models and thought that the only difference is the quality how its made, balance, etc and that £7 cheap trowel had it all going for and had good reviews.. except I didn't know why those more expensive trowels came worn in. only now I realize it after actually using it
am I right on that?

 

Alright well I have to say thank you so much all you guys for the advice/tips
Finished my first 6m2 , about 70m2 more to go, however in the end it turned out 9/10 for a beginner at this, would have been 10/10 If I hadn't messed up with a bad plaster in first place

Somehow blended in the old plaster with the new and it's all smooth as a you know what.
I think the biggest tip here is, is to just go and do it, there's no way you can learn everything by just watching some videos, just have to figure things out and go with the flow. I got a few places where I will need to probably touch up with a filler and a bit of a sander after its dry but very pleased with how it turned out

By the end of it I'm sure I won't be a total pro but should be very decent at this.
thanks again
I'm sure I will have some more questions...


Oh actually I got a question about my cheapo £7 trowel, should I try and rough it up myself with an angle grinder the way it was done in the shop for the 7x more expensive trowels?

 

well it looks like a piece of ''art'' now while its drying

Anyway I have decided to get another trowel, can anyone suggest me some decent one? By decent I mean one of the best or the best there is at a reasonable price? I checked those pleziflex ones but realized that they are just finishing trowels not all-in-one trowel and I need 2 trowels in that case...

this is what I have found myself:

http://www.toolstop.co.uk/marshallt...ss-steel-plasterers-trowel-13-x-5-inch-p32928
Marshalltown MPB13GSD 13x5-inch Gold Stainless Steel , around £37 with coupons at toolstop.

was wondering if there's anything better?

 

Well I can say that I have finished doing the 75-80m2 that I had, didn't had much time when to do it actually but in the end it took me around 30hours over 3.5days to do everything. It took me slightly longer because I don't have stadard sized rooms with large straight walls but it was a loft conversion with all kind of shaped small areas + a stair area to do.

I can honestly say now after doing this myself that the internet is full of fake info about how hard is it to do it.. it's **** easy to do and to get a decent finish.
there are even special courses for plastering? probably the schools/other plasteres have wrote that stuff all around so people don't do it themselves
out of the 3.5days I would say it took me the first 2days to kinda figure everything out and get a good grip at it and become decent at it.
However.. It's very tiring and very fast paced work.

The only time I messed up was at first when I tried to use out of date plaster and it fuked up the first wall due to setting off instantly.

expenses to do 75-80m2 :

8bags of the red stuff - £43
2 joint tape rolls -£7

tools:
very **** trowel -£7 (threw it out after the first wall)
very good marshalltown trowel- £36
hawk - £9
mixer attachment- £2.5
2 new buckets - £3
new brush/sprayer- £2

so £50 for the materials and £60 in tools, saved probably around £700 by doing it myself and just buying the tools/materials.

Cheers everyone, at least learned a new skill

 

Will do when I have some time,
Thanks Devil for your suggestions in past

Yes, to get the finish you want it takes lots of sweat and grunt, most definitely not a job that is physically easy, after each day I was just heavily exhausted..I would say it's much better workout than you can get in a gym as if you don't do it fast/hard enough you risk messing it all up