How to dilute harden LP (CA?) Adhesive? - Page 1
Forum section: electronics / beginners

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 23, 2013, 03:45:32 pm
content: i have an LP adhesive similar to below picture, not sure the standard name. Its been years in storage half full (in 3 litres tin), now i want to use it, but its 50% harden it cannot flow freely. I wish there is a way to recover and reuse it. googling gave me some hint that its built on polychoroprene and polyvinyl acetate (maybe), and to dilute it using ethyl acetate or acetone, am i in the right direction? can i try thinner? can you give better suggestion as diluter, hopefully that i can easily purchase from normal hardware store. thanks.

author: robrenz
author_rank: Super Contributor
timestamp: July 23, 2013, 05:01:35 pm
content: Hello Mecha!If you look at this msds from an old style contact cement the solvents are mainly Toluene with smaller percentages of MEK and naphtha. If you add those three in the approximate ratios to each other shown I think it should work.Getting the MSDS for the Dunlop LP would be better

author: G7PSK
author_rank: Super Contributor
timestamp: July 23, 2013, 05:36:29 pm
content: I don't know about the rest of the world but in the UK the solvent/thinners for contact adhesives costs more than the glue so if it drys out its cheaper to buy more glue rather than the thinners.

author: SeanB
author_rank: Super Contributor
timestamp: July 23, 2013, 06:07:56 pm
content: True, the road marking paint I use every so often for symbolic signage and demarcation has a thinner you can use to clean the brushes and rollers it is applied with, or to thin it down for spray application. The thinners costs the same per litre as the 5l of road marking paint. I consider brushes and rollers along with paint trays that are going to be used with this paint as disposable items. It is cheaper to go and buy the cheapest packs of brushes ( and work them a little in turps to get the loose bristles out if you really care about the work you are going to paint, not a problem if it is tar) and use them one brush per job, or one brush per hour if you are going to be using a lot of paint. Only paint I have met that is touch dry in under 3 minutes, it almost dries on the brush while you are applying it.

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 24, 2013, 04:02:06 pm
content: we have low cost thinner here that cost 1/3 as the lp adhesive. and maybe i dont have to pour much into the harden adhesive i guess, maybe 1/5 in volume of harden adhesive? but i'm not sure thinner can do hopefully i can try in small amount and wont make the lp into bubbles of jellies. buying a 3-5l thinner wont hurt here as its one of my mostly used item (and it wont harden in long time storage). Robrenz, whats the layman term for toluene? so i can ask hardware shop. if i ask them for "toluene" i'm sure they will shrug or go "huh!!??" with left eye shrinked. thanks for the link but is "contact cement" similar to "contact adhesive" since i dont think the one with me is highly flammable. its yellowish or brownish liquid glue it smells good i believe this is inhaled by drug addict.

author: robrenz
author_rank: Super Contributor
timestamp: July 24, 2013, 05:02:25 pm
content: Three names hereThe contact cement I am familiar with is also brown/amber colored and somewhat rubbery when completely dry.

author: G7PSK
author_rank: Super Contributor
timestamp: July 25, 2013, 07:42:22 am
content: Cellulose thinners will damage the glue and quite likely any thing that the glue is applied to. There are several grades of cellulose thinners the best for finnish work is expensive the lower grade is for primers etc and then there is what is often referred to as gun wash as it is the cheapest and used for cleaning the spray gun. If you use that with paint there will be a bloom on the paint when it drys. This is most likely the thinner that you are referring to as being one fifth the cost of the glue, last time I purchased some it was cheaper than petrol, you could run the car on I expect if it wasn't for the damage it does to plastic's and rubber.