Tiny "chunks" in estapol finish

[IRONxMortlock]

Hi folks,

I'm currently making a bed from tassy oak and I'm at the stage of finishing it.

I have stained the timber and applied a single coat of estapol's satin finish. Following the directions on the can, I Iightly sanded the first coat of estapol and then, after wiping away the dust, began to apply the second coat.

To my horror I found tiny particles appearing in some areas in the finish! On one area which isn't going to show I tried to pick/rub these out but it just seemed to create even more chunks. This is very disappointing as the finish after applying the first coat looked absolutely beautiful. I'm now wishing I'd just done a single coat only.

I have the following questions:

1. How do I get rid of it?
2. What causes this effect?
3. How can I prevent it in the future?

Thank you very much for your help,

M

EDIT

Here are some pictures.

[Harry72]

Was it a fresh can of estipol? Was your brush surgically clean?
The 1st picture looks like a reaction, but the 2nd closer picture there definitely something contaminating it.
Getting rid of it, if the estipol is still soft/green a light heatgun and a scraper will take the majority of it off, then a light sanding. Or sand it off completely, being stained you will probably need to restain it.

[Ashore]

Mate was the stain and estapol the same brand and compatable


Rgds

[IRONxMortlock]

Thanks for the replies!

Yep, same brand (wattlyl with "traditional craftsman stain) and no mention of them being incompatible.

What's strange is that this didn't happen when I first applied the estapol. The first coat (directly onto the stained timber) worked like a charm. After it had dried it was lovely and smooth and it felt even better after the light sand.

The second coat went on smoothly but then these chunks started to appear after I had finished applying it. I first opened the tin on Sunday and have taken care to keep it clean. I was using a clean brush.

[DJ’s Timber]

Another thing to think about, what was the temperature and humidity like at the time of application, was it in the recommended range stated on the can

[IRONxMortlock]

Another thing to think about, what was the temperature and humidity like at the time of application, was it in the recommended range stated on the can

Yep, no worries. A lovely day here in Brisbane. Max of 26 and 61% humidity. I did this around 9AM so it was probably about 18 or 20 then. Well within the tolerances.

[Big Shed]

It almost looks like the second coat is lifting the first coat. It also appears to be following the grain pattern, which makes me thinks that the stain is the underlaying problem.

How long between applying stain and first, and between first coat and second coat?
If there was insufficient time between applying the stain and the first coat, or high humidity, then the first coat would not have through dried, the solvent in the second coat then attacked the uncured first coat.

If lifting is the problem, then all is not lost, just let it dry thoroughly, ie a few days as there is trapped solvent in the film, then sand smooth and re-coat.

The surface imperfections are too big to be from contamination in the varnish, you would have noticed them, or rubbish in the brush, you would have seen that when you applied the varnish.

[IRONxMortlock]

It almost looks like the second coat is lifting the first coat. It also appears to be following the grain pattern, which makes me thinks that the stain is the underlaying problem.

How long between applying stain and first, and between first coat and second coat?
If there was insufficient time between applying the stain and the first coat, or high humidity, then the first coat would not have through dried, the solvent in the second coat then attacked the uncured first coat.

If lifting is the problem, then all is not lost, just let it dry thoroughly, ie a few days as there is trapped solvent in the film, then sand smooth and re-coat.

The surface imperfections are too big to be from contamination in the varnish, you would have noticed them, or rubbish in the brush, you would have seen that when you applied the varnish.

I think you maybe right, the second coat is lifting away the first. The chunks seem to be made up of the finish itself.

I waited a full 24 hours after applying the stain before I put on the first coat of estapol. I waited another 24 hours before the second coat but it did rain during that day (Yay for Brisbane!) so it may not have dried properly.

I'll take your advice and let it sit for three days and then sand before I try a third coat. I'll post back here with the conclusion.

Thanks for your help!

M

[Big Shed]

After 3 days test the film by sanding in an inconspicous place, if it isn't cured it'll clog the sand paper, if it is cured you'll be able to sand real easy.

[speedy]

Hi,
Up here in North QLD, in the rainforest I have to let estapol dry for at least a week between coats, otherwise it will lift the previous coat.
I now use lacquer or polyurathane, much less trouble and so much quicker, I can do three coats in a day or two, instead of three weeks.

[bitingmidge]

Speedy,

Isn't Estapol polyurethene?

Cheers,
P

[durwood]

Stating it's estapol doesn't narrow the field enough.

Estapol is just the brand name as there are many different Estapol clears knowing which one would be of some help.

The singly pack ones although polyurethane by name are really only enamel products.

Usually true polurethane would signify a 2 pack product. I think these are the ones Speedy is refering to. Put in hardener and the drying process alters dramatically, it will dry rock hard real quick. Even if the temperature drops below 15 C it will still go off though cold slows it down.

The one pack products can need far more than 24 hours, Bigsheds observation of it following the grain appears to be on the right track.

The stain in the dark grain areas has probably not dried as much as the other areas, as it may have soaked up more stain. If it was oil stain the stain will mix in with the one pack clear (same solvent) and altering the drying time.

Once the single pack enamel sets its Ok but if it hasn't dried out properly any strong solvent coating will attack it and it will turn into a jelly. swelling up and then not drying properly.( like the photo's. ) It doesn't dry like lacquers it forms a skin by mixing with oxygen in the air. Thats why you get a skin on the top of the paint left in the tin.

If after a few days its still not hard it will never be, strip it of and start again. I don't think the end result of your labours rubbed back and finished will ever be a good durable surface for a bed.

Can you post the type of Estapol clear and stain?

[IRONxMortlock]

I'm using this finish and I used this stain.

[Frank&Earnest]

Had a similar experience with Wattil gloss Estapol (the old white can with the picture of a horse). My post-mortem, FWIW, was that it was an old can and it had started to polymerase. The brush was collecting, breaking and spreading the little hard bits. Hard to see while wet but the hard bits would protrude when the rest flattened out.

Luckily it was reasonably easy to remove: it created a thick hard coat that peeled off when carefully lifted with a blade.

Good luck.

[speedy]

Speedy,

Isn't Estapol polyurethene?

Cheers,
P

Estapol is the brand name for Wattyl clear finish paint, some are 2 pack poly, some are single pack poly , some are enamel and some are water based acrylic. I personally won't use wattyl clear finishes again, I now only use cabots clear finishes.