Tin of bitumen

[Chris Hogg]

I have inherited a very old 5l tin of Evode rubberised bituminous waterproofer that's the consistency of very thick treacle. It must be at least 25 years old, I should think. If I can add a little something to it to thin it down to a workable consistency, it would save me having to ditch it and buy new. But what should I add? It says 'clean brushes with water', suggesting an emulsion, but I thought these things were bitumen solutions in an organic solvent. So should I use water or something like white spirit or petrol to thin it down?

[Brian Reay]

If it is (like) the stuff I?m thinking of, stand it in a bucket of hot water. It becomes much easier to apply with a brush but don?t hang around in cool weather. As for cleaning brushes, forget it. Use a cheap one and throw it away.

[Tim Lamb]

In message , Chris Hogg writes

Prolly got Asbestos fibres in it:-)

I whack mine on with a putty knife and then use a hot air gun to soften and smooth off.

>

[tabbypurr]

There are 2 types, solvent based - use paraffin - and water based. Sounds l ike the latter.

NT

[Thomas Prufer]

Take a small sample and try? This would also avoid "I'll add just a tiny little bit of thinner, oops the result is way too thin..."

Using the wrong solvent will make the whole batch unusable: white spirit in water-based can cause clumping. And the clever plan of adding a bit of copper sulphate to water-based bituminous roof paint to prevent moss will cause some to curdle or coagulate. DAMHIK.

Thomas Prufer

[Brian Gaff (Sofa)]

Well having used that stuff many moons ago, It was always thick and sticky, it also tended to give me a headache if I used it too long! There were all sorts of recipies to make it go further from engine oil to exotic chemicals.

Brian

[Brian Gaff (Sofa)]

Yes indeed, and be aware it stinks even more when its warm. I'm sure that gas must be something pretty nasty. Brian

[Chris Hogg]

Thanks for the suggestions. A small sample to start with - warm it gently over hot water - add a little water if necessary - try applying the stiff stuff with a spatula and then using a hot air gun - all ways to go.

Incidentally it's a UBM own label product (United Builders Merchants), with Evode in small print in one corner of the label. So according to this history of Evode bitumen products, it's probably Evoseal 202, and could date from the 1970's or 80's!

[Martin Brown]

My guess would be something between petrol and kerosene to replace the volatiles that have been lost. ISTR it originally was naphtha solvent.

Try it on a small amount to see which works best and in what proportion.

[newshound]

+1

[tabbypurr]

CuSO4 is far too soluble. Try cu powder or fine grain.

NT

[Andrew]

If it is like Isoflex that 'cures' after being applied, then it will need a solvent like xylene. Isoflex used to use this but when Ronseal bought it in the mid 1990's they changed the formulation to make it xylene-free. Needs a special solvent to clean off splashes and brushes. White spirit won't touch it, but you can use petrol to do the main cleaning.