Cuprinol - beware

[Jim McCrae]

I am in the process of refinishing the woodwork on my Morris Traveller. After painstakingly sanding it back to bare wood, I did as others have suggested and applied Cuprinol Wood Preserver (Clear) prior to re-varnishing. The Preserver sounded suitable - "for interior and exterior use prior to painting, staining or varnishing" . I followed Cuprinol's instructions to apply two coats and leave for 16 hours before painting etc.

Two weeks later the preserver has still not fully dried. The surface remains soft and feels tacky or waxy. It is impossible to sand as it continually clogs the sandpaper. Cuprinol Customer Care diagnosed this as "slow drying" (No MY FAVOURITE CAR IS A DATSUN CHERRY!) and suggested wiping with methylated spirits and leaving for a couple of days to fully dry. This didn't work. I am now laboriously scraping and sanding the wood back to a bare surface and will apply varnish directly to the wood without any preserver.

It appears that Cuprinol has recently changed the formulation to water rather than spirit based so this might go some way to explaining the problem. I have complained to them that this product is not fit for purpose and will see what they say.

[mogbob]

Perhaps , if the reply is along the lines of " nothing to do with us , Sir " Trading Standards would give you and unbias opinion.
Frustrating I know but I hope there is a satisfactory conclusion to this for you.
Bob

[geoberni]

I can only imagine that the water based product is reacting with remnants of any other products the wood has previously been treated with; which could be anything over the past 50 years if original wood.

Was there a caution to 'Try a small area first for compatibility'?

it'll be interesting to see what response you get.

[James k]

I can only imagine that the water based product is reacting with remnants of any other products the wood has previously been treated with

I suspect this too. I recently treated a new wood frame with Cuprinol and it dried fine. It did take longer than the old stuff and felt tacky while it was drying, but I was able to varnish it after a couple of days.

It did raise the grain guite a lot though so it needed some rubbing down after drying.

[jagnut66]

It appears that Cuprinol has recently changed the formulation to water rather than spirit based

A shame they had to mess with it.
For what reason I wonder? More Health & Safety BS gone mad I suspect!
It used to work really well.
Thanks for posting up a warning, I shall have to look for something else then.
Best wishes,
Mike.

Edit: What about this as an alternative?
https://www.googleadservices.com/pagead ... RBY&adurl=

[geoberni]

A shame they had to mess with it.
For what reason I wonder? More Health & Safety BS gone mad I suspect!

Safer for the end user applying it and far safer to make it.

When I was a kid, as a Carpenter my father used all sorts of glues when making stuff, some of them 2 part substances.
I remember one was acid (or perhaps alkali) activated.
All I remember was that if the activator was spilt on the concrete garage floor, it started to make the floor fizz!!

But back on topic, it does appear that the product has been reformulated.
The previous issue of the Safety Data Sheet (2016) described it as Solvent based, the latest 2021 version says water based.

[jagnut66]

I have to say I have similar experiences with other 'water based' wood sealants and dyes, which has put me off them.
Therefore I shall continue to source the solvent (spirit) based ones whilst I still can, as I regard them as far better.
Best wishes,
Mike.

[JOWETTJAVELIN]

Better stock up, this could go the same way as Dum Dum.

[kennatt]

Better stock up, this could go the same way as Dum Dum.quote]

And nitromores, celly thinners, weed killer,rat poison etc etc

[Mick Lynch]

Better stock up, this could go the same way as Dum Dum.quote]

And nitromores, celly thinners, weed killer,rat poison etc etc

and Spangles

[les]