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adem
8th October 2018, 08:34 PM
Hi all, i've been trying to make some wipe on poly but when i mix with methylated spirits the oil based polyurethane goes gluggy and doesnt mix together. Am i doing something wrong. Here is the dinning table im painting its Australian red cedar https://uploads.tapatalk-cdn.com/20181008/78bf7923d4ea5e2629c278a5cb687049.jpg

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Bendigo Bob
8th October 2018, 08:40 PM
I have been using white spirits (for dry cleaning) and it works beautifully Adem, and I mean beautiful. I just use an old soft cloth from winter undershirts, folded and wipe it on kind of like brushing, just one or two sweeps and move on. Don't sue metho as it is not compatible. Mix 50/50 in enough of an amount you will use within the next few days, no more

ian
9th October 2018, 01:37 PM
Hi all, i've been trying to make some wipe on poly but when i mix with methylated spirits the oil based polyurethane goes gluggy and doesnt mix together. Am i doing something wrong. depending on where you purchased your "metho" and how old it is, the water content of the "metho" can be 50% or more.
as Bob suggests you need to use a petroleum solvent with an oil based finish.

Bendigo Bob
9th October 2018, 03:10 PM
Shellac = metho
Poly = shellite or similar (white spirits, which I 'think' is a more refined turps, like paint thinner)

Not sure of the chemistry behind it but I know you need to remember the difference, in any case they behave quite differently

Bendigo Bob
9th October 2018, 03:11 PM
By the way - I WANT THAT SLAB :) :)

ian
9th October 2018, 04:05 PM
:whs:

adem
9th October 2018, 08:56 PM
Thank you for that info Bob, ill give it a try and yes it is nice slab.

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adem
9th October 2018, 09:01 PM
Ian it just digger brand and purchased it last week.

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crowie
9th October 2018, 09:46 PM
For toys, not furniture I make up a wipe on poly from the following formula...
30% Pure Tung Oil
40% Clear Satin Polyurethane [oil based]
30% Turps
Someone on the forum gave me that formula a couple of years back and it works great for me...

This was the latest toy truck with Australian red cedar bonnet.... .443681 443682

Cheers, crowie

Bendigo Bob
10th October 2018, 07:10 AM
Yes, good you mentioned that Crowie!

Did a table top the other week. It was a rescued old farmhouse table I managed to end up with a breakfast table out of it for the client (Nostalgic reasons, about 125 years old, in the family for generations but last 50 years in the shed being abused, sigh!)

The wood was SO soft I fretted over it and did that same mix you mentuion for the first two coats, just with BLO instead of Tung oil (coz that's what I had :) ). Worked a treat. The oil helps the mix bite in deeper. I followed up with about 8 coats of the poly/shellite mix. Here's the result

443696

I tested for durability on a scrap and was real pleased.

taz01
10th October 2018, 08:09 AM
Hi allI,

Is the wipe on poly you can get from Bunnings no good, or just pricy compared to a homebrew recipe?

Bendigo Bob
10th October 2018, 08:37 AM
It's good alright, but way too pricey

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crowie
10th October 2018, 08:37 AM
Hi allI,

Is the wipe on poly you can get from Bunnings no good, or just pricy compared to a homebrew recipe?

I make my own as was recommended to me and only do it in small quantities....
I got the Satin Polyurethane from Bunnings on special, plus turps from them while purchasing the Tung Oil direct from Scenerys in Melbourne

PaintMan
14th October 2018, 10:37 AM
I mostly use PreCat spray finishes but as a retired paint chemist I also often make my own coatings for use on small articles.I sometimes use shellac based sealers and blends of tung oil/orange oil/wax for specific topcoats. This material can be easily wiped on as the orange oil is a slow drying component. One other option to consider with your Tung Oil is to dilute with some pure tupentine that is available at most hardware outlets. This is a good solvent for tung oil as well as in solvent based PU Alkyds such as Cabothane etc. I have also seen poor results from using weaker solvents such as white spirits and some retail "mineral Turps" where the strength (aromatic content) is lower than pure turps and causes milky films on drying. This milky effect can be quite pronounced under adverse weather such as lower temperatures in winter. Some "mineral Turps" retailed in Australia are not high quality and care is required to source a reliable supplier.
Paintman