What's in West System cleaning solvent 855, 850, 820 ?

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Boo2

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Hi,

I've just bought some West System epoxy and related materials for bonding some pads and mounting stringers into the boat and I saw in the instructions that the pumps should be cleaned with West Systems 855 cleaner. This is available from eg marinestore in the UK and seems a lot cheaper than the 850 cleaner. There is also available 820 cleaner and I'm a bit puzzled as to what the difference between these is and how they differ and whether they are any better or worse than acetone which I already have ? Anyone know what they're made of ?

Thanks,

Boo2
 
855 is a fairly harmless cleaner, containing small quantities of propylene glycol and dipropylene glycol (both solvents). 850 is a more aggressive solution, containing fairly high concentrations of MIBK (methyl isobutyl ketone) and xylene - again, both solvents.
 
Have you tried methylated spirits? The purple dyed stuff. I don't know how the costs compare in your country but last week I bought (in Malta) a 5-litre plastic jerry can for €16 which is cheaper and more effective with epoxy than acetone for which I pay €22 per 4-litres.
 
With many products, the most certain way to determine what is in them is to visit the manufacturer's website and look for the MSDS (Safety Data Sheet) which will give the main active components and also advise on safe handling.

Rob.
 
Epoxy resins are water soluble, so you do not need harsh and sometimes harmful cleaning chemicals.

Methylated spirits can be used to thin epoxy resins as well as cleaning it off if not set.

Warm soapy water is also good for cleaning unmixed resin,

Vinegar is also a good cleaner for pumps.

And best of all, the above are all cheaper than, and less harmfull than chemical cleaners.

Good luck and fair winds. :)
 
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Mentholated spirits can be used to thin epoxy resins as well as cleaning it off if not set.
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It's just a small point, but as the OP specifically mentioned 'West Epoxy', please don't mention the use of solvents as thinners. It's poor practice and specifically discouraged by the manufacturer. The application of heat is the only recognised way of thinning West System epoxies as the change in its physical properties by adding any thinners can be disastrous.
 
Mentholated spirits can be used to thin epoxy resins as well as cleaning it off if not set.
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??? methylated ?

Google spellchecker strikes again !
 
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Maybe a little late in responding but feel I should point to my own information which suggests that it is not correct to state that epoxy resins are water soluble. In fact, only the hardener used in West System is water soluble and a hardener pump can indeed be cleaned up with warm soapy water.

However, to clean up the resin pump it is necessary to use either West's cleaning solvent or cleaning solution (850 and 855 respectively). I guess acetone may do a similar job but haven't tried it.

It is interesting to hear that methylated spirits can be used instead of 850 or 855. Haven't heard this before but will give it a go for cleaning tools (not on a workpiece) and see how it goes versus 850.

Finally, and as has already been said in this thread, West's UK supplier, Wessex Resins, does NOT recommend thinning. In fact, they say that no attempt should ever be made to thin. I presume this has to do with degrading the structural properties of the epoxy. Thin at your peril, then!

Best wishes

Mike
 
thewoodenboatman said:
Maybe a little late in responding but feel I should point to my own information which suggests that it is not correct to state that epoxy resins are water soluble. In fact, only the hardener used in West System is water soluble and a hardener pump can indeed be cleaned up with warm soapy water.

However, to clean up the resin pump it is necessary to use either West's cleaning solvent or cleaning solution (850 and 855 respectively). I guess acetone may do a similar job but haven't tried it.

It is interesting to hear that methylated spirits can be used instead of 850 or 855. Haven't heard this before but will give it a go for cleaning tools (not on a workpiece) and see how it goes versus 850.

Finally, and as has already been said in this thread, West's UK supplier, Wessex Resins, does NOT recommend thinning. In fact, they say that no attempt should ever be made to thin. I presume this has to do with degrading the structural properties of the epoxy. Thin at your peril, then!

Best wishes

Mike
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G'day Mike,

The reference to epoxy resin being water soluble referred to resin that has not been mixed with a hardener, I have washed out many near empty containers with just a running tap for many years.

Also note: I only advise the thinning of epoxy resin to prime and penetrate ply or some timbers, after this initial coat I cover with standard spec' resin, and I never advise anyone to to thin epoxy for structural work.

I hope this clears things up for you.

Good luck and fair winds. :)
 
I think Wessex suggest that if you need to thin it, it is too cold ! Warm it up;its pretty runny then.
As you say, priming is the goal, but that doesnt imply penetrating deep into the wood at all. It is only the surface you need to prime, to ensure that the joint isnt starved of resin. The joint is resin to resin, so soaking the wood doesnt help the joint.
 
gjgm said:
I think Wessex suggest that if you need to thin it, it is too cold ! Warm it up;its pretty runny then.
As you say, priming is the goal, but that doesnt imply penetrating deep into the wood at all. It is only the surface you need to prime, to ensure that the joint isnt starved of resin. The joint is resin to resin, so soaking the wood doesnt help the joint.
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I agree, But it certainly improves it's resistance to moisture if exposed.
 
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