Thread: West System Use?

I've always kept the small clear graduated plastic medicine cups.
If you know a nurse get her to score you them in bulk.
I pour the resin in first then top up with hardener and usually after mixing transfer to another cup and remix. Read somewhere this mixes the resin in the bottom thoroughly?
I have joint gaps in my concrete workshop floor wot are a menace when moving machinery,I use the leftover glue mixed with dry sand to fill these a metre at a time.
H.

Hi Cava

For large quantities - 100-1,000 millilitres - I use a West pump.

For small quantities - 20-100 millilitres - I use disposable medicine glasses. Bought from a super-discounter.

For tiny quantities - <20 millilitres - I use two bamboo satay sticks. Five drops of resin, change sticks, one drop of hardener, stir slowly. Trick is to ensure all drops are the same size, especially the hardener which is less viscous than the resin.

I rarely, if ever now, mix greater than a litre as exothermic reaction becomes an issue.


Cheers

Graeme

And just from a slightly different viewpoint.....

I always put the part 1 in first. Reason is that I use a 5:1 ratio system and measure with a scale. This way if I go a bit over when adding the second part it is a smaller percentage of what is already measured. Have had no problems uncured mixes.
The scale is one of the so called "jewellers scales" available on the interweb for under$50 delivered and it's worked well so far.

Well, I have been playing with West System with some good results (at least I think so). But today the ambient temperature was warmer than all the previous batches I had made, and it was eventful to say the least.

Typically I have been using 50ml quantities.

The mix went off so quick, and started fuming and heating up so that it was painful to hold the mixing cup - the things you learn.

Next time I will use the slow hardener 206!

Originally Posted by cava

Well, I have been playing with West System with some good results (at least I think so). But today the ambient temperature was warmer than all the previous batches I had made, and it was eventful to say the least.

Typically I have been using 50ml quantities.

The mix went off so quick, and started fuming and heating up so that it was painful to hold the mixing cup - the things you learn.

Next time I will use the slow hardener 206!

Hi Cava

Temperature is a factor, but Melbourne was only 30* yesterday, and unless you were in a particularly sunny spot, or a particularly hot spot, then it should not have had such a dramatic effect.

Did you change your mixing container to a deeper one? Shallower containers help avoid exothermic reactions?

Could you have accidentally added too much hardener?

Could there have been some contamination - dirty container, pre-used container, different type of plastic in container?

Not sure what went wrong, Cava, but some batches of epoxy just seem hornery !

I always use WEST slow hardener 206 - it just gives me more working time - and if I have the slightest concerns I use the ultra slow hardener 209. Only real issue with them is that on vertical or sloping surfaces, slump becomes more of an issue.

These do give peace of mind, but I am not convinced they give a lot of extra protection against exothermic reactions. I still occasionally get exothermic reactions with the slow hardeners, almost always with large mixes in small containers, but it is so long since I used 205 that I cannot compare the frequency.


Cheers

Graeme

Hi Graeme,

Same West System container, using effectively the same quantity. The container was clean.

My shed was hotter than when I mixed batches previously. From memory the temperature previously was low 20'sC.

I must admit that I was surprised at the reaction, given my previous experience, and effectively lost 80% of the mix going off.

If I get my act together, I will see about getting the slow hardener today.

George

Hi Cava

What you describe sounds like a change due to a higher temperature.

Typically, epoxies are specified at "room temperature" which for West Systems seems to be 22°C (around 72°F).
The West System manual suggests that West System 205 Hardener is formulated for a temperature range of 5° to 30°C. (At 22°C pot life for 205 hardener is given as 9 to 12 minutes.
At 30°C you are probably down to well under 5 minutes from initial mixing.

Perhaps, outside the coldest months of the year, you should standardise on the 206 hardener.

As mentioned above, using a deep mixing cup can lead to problems; exothermic reactions like this increase exponentially (logarithmically?) as they get hotter, so once they reach a critical temperature they speed themselves up and it's game over.

I once had a batch of Techniglue harden and start to smoke in about 15 mins when I left it in a neat blob on the board (I always mix on a flat surface) and it's not meant to set for 8 HOURS!

Bought 206 today, so all should be good for the next batch (whenever that will be ).

Originally Posted by cava

Same West System container, using effectively the same quantity. The container was clean.

My shed was hotter than when I mixed batches previously. From memory the temperature previously was low 20'sC.

I must admit that I was surprised at the reaction, given my previous experience, and effectively lost 80% of the mix going off.

Hi George

I'm also a little surprised by what you report. Losing 80% of a 50 ml mix.
West Systems suggest that at 22 degrees, pot life (with the 205 hardener) is only 10 minutes. Typically around 2 to 3 minutes of that time would be mixing.
If you are used to a significantly longer pot life it suggests to me that the previous temperature in your shed was well under 20 degrees.

Do you have a copy of the West Systems User Manual?

Originally Posted by ian

Do you have a copy of the West Systems User Manual?

Yes.

PS. When I discussed my experience with the Marine Chandler that I bought the West System through, he also recounted a similar/weird experience that he had, had in the last few weeks. The prevailing thought he had was some sort of atmospheric aberration was the cause ie temperature, humidity, pressure etc.

my own thoughts are that using the 205 hardener in Australia would typically be pushing the upper end of it's temperature range which seems to be about 30 degrees C .


Given West System's chart, the 205 hardener might be better suited to temperatures below 25 degrees.

It would only take a small variation in the properties of either the 105 resin of the 205 (particularly their density) for the required mix ratio to change leading to a big change in pot life.

For best results I used to mix by weight. Depending on the angle the measurement may appear to be correct or to little/to much. This also will help remove any doubts of improper mixing.

Sent from my SM-G935W8 using Tapatalk

Originally Posted by ian

my own thoughts are that using the 205 hardener in Australia would typically be pushing the upper end of it's temperature range which seems to be about 30 degrees C .

Spot on Ian.

Experience is a great teacher!

George