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Synthetic paint thinners PT8 vs. white spirit

Are they the same thing?

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AJAX30/10/2021 17:43:10
395 forum posts
42 photos

I'm hoping that someone with some knowledge of paints and thinners can offer their opinion.

I have used Paragon Paints enamel paint on two or three recent projects. I have brushed (not sprayed) and cleaned up using white spirit without difficulty.

In their instructions, they state that we must use their own brand PT8 synthetic thinners.

"Please do not make the mistake of using cellulose or other types of thinners with our enamels, this is not a cellulose thinners and is manufactured specifically for the Paragon range of enamel paints."

However, I have checked the MSDS datasheet for PT8 thinners and white spirit and they appear to contain the same substance.

CAS No.: 64742-88-7

Unless you can tell me a reason to do otherwise, I will continue to use white spirit for cleaning and thinning for spraying (if the need arises). As you might guess, white spirit is much cheaper.

  • PT8 thinners (1L for £9.18)
  • White spirit (2L for £3.99 from a well-known store)
Dave S30/10/2021 18:41:43
374 forum posts
90 photos

White spirit is not cellulose thinners, so I just that part is true

Dave

Dave Halford30/10/2021 19:07:45
2100 forum posts
23 photos

Any spraying thinners are normally 'fast'. Cellulose thinner is just about the fastest you can get, so much so that paint not immediately landing on the job is actually dry by the time it has travelled 5 ft or so. This reduces runs to a minimum.

White spirit is quite slow, household gloss taking 16 hours to dry properly.

So if Paragon paint dries relatively fast for brush paint say to or three hours, white spirit will slow it down and the overspray will paint surfaces you didn't want painting like the windows.

You could have 'cleaned up' just as easily with cellulose, which which is very aggressive and so is very good at removing paint. That doesn't mean you can thin any paint with it and still use it as paint

Dick H30/10/2021 19:19:13
110 forum posts
1 photos

See wiki on "White Spirit" https://en.wikipedia.org/wiki/White_spirit. Both white spirit and the material supplied under the CAS (Chemical Abstracts) No. 64742-88-7 are hydrocarbon mixtures, i.e a bit of straight chain alkanes, cyclic alkanes perhaps a touch of aromatics. The mixtures are usually classified by their boiling points. Your mix is White spirit type 0, (See https://wedocs.unep.org/bitstream/handle/20.500.11822/29645/HSG103W.pdf?sequence=1&isAllowed=y), it appears to be a bit lower boiling, ie. more lower alkanes. So white spirit in general would probably work but this particular cut would be best.

Chemically celullose thinners are a different kettle of fish ( see https://en.wikipedia.org/wiki/Lacquer_thinner) covering more polar solvents such as ketones and esters (ie. things like acetone and MEK and esters such as butyl acetate (pear drops smell)).

AJAX30/10/2021 19:27:53
395 forum posts
42 photos
Posted by Dave Halford on 30/10/2021 19:07:45:

Any spraying thinners are normally 'fast'. Cellulose thinner is just about the fastest you can get, so much so that paint not immediately landing on the job is actually dry by the time it has travelled 5 ft or so. This reduces runs to a minimum.

White spirit is quite slow, household gloss taking 16 hours to dry properly.

So if Paragon paint dries relatively fast for brush paint say to or three hours, white spirit will slow it down and the overspray will paint surfaces you didn't want painting like the windows.

You could have 'cleaned up' just as easily with cellulose, which which is very aggressive and so is very good at removing paint. That doesn't mean you can thin any paint with it and still use it as paint

Thanks Dave, that's useful information. Looking at the details (below) it would seem that white spirit could slow things down a bit. But that wouldn't be problem for me.

Touch dry:- 2 Hours. Firm dry:- 6 Hours. Hard dry:- 12 Hours, @ 20ºC.

Dick H30/10/2021 20:03:38
110 forum posts
1 photos

If you go with too a volatile a solvent when applying the paint you may get artifacts such as an "orange peel" surface.

Andrew Tinsley30/10/2021 21:21:36
1615 forum posts

I am interested in the OP's original question, because I use Paragon paints.

The question was "What is the difference between white spirits and Paragon P8 thinners?" The OP's researches indicate they both contain similar ingredients. So does anyone know the answer? Neither I, nor the OP, are really interested in cellulose thinners, as it is not suitable for Paragon enamel paints.

Andrew.

Edited By Andrew Tinsley on 30/10/2021 21:24:54

AJAX30/10/2021 22:05:20
395 forum posts
42 photos
Posted by Andrew Tinsley on 30/10/2021 21:21:36:

I am interested in the OP's original question, because I use Paragon paints.

The question was "What is the difference between white spirits and Paragon P8 thinners?" The OP's researches indicate they both contain similar ingredients. So does anyone know the answer? Neither I, nor the OP, are really interested in cellulose thinners, as it is not suitable for Paragon enamel paints.

Andrew.

Edited By Andrew Tinsley on 30/10/2021 21:24:54

For my use, price seems to be the biggest and possibly only difference. I will continue using white spirit to clean brushes and if I'm tempted to try spraying (not likely at the moment due to lack of space) then I'd try white spirit too.

John ATTLEE30/10/2021 22:13:26
28 forum posts

Dear All,

I use synthetic paints for my classic commercial vehicle projects. Cellulose thinners will ruin any synthetic paint if you mix it with it. However, this property makes it very good for cleaning brushes and spray guns because it breaks the paint down. I quite often use white spirit for economy. For a really good job I would use the correct thinners from the paint manufacturer.

John

Ramon Wilson30/10/2021 22:49:18
avatar
1401 forum posts
448 photos
Posted by AJAX on 30/10/2021 19:27:53:
Thanks Dave, that's useful information. Looking at the details (below) it would seem that white spirit could slow things down a bit. But that wouldn't be problem for me.

Touch dry:- 2 Hours. Firm dry:- 6 Hours. Hard dry:- 12 Hours, @ 20ºC.

As a long time 'paint applier' trying to obtain good finishes with a variety of products on varying substrates I really have had my fair share of disasters over time. Like many other situations it's always accompanied with a 'wish I hadn't done that' regret.

Best advice I can offer is whatever paint type you choose is to keep the products compatible and use the recommended thinner - something learnt long ago and always adhered to now. Mixing differing paint finishes from layer to layer can create some very unexpected results too. If you (oneself) don't keep to this principle then you can't blame the paint if it goes wrong, if you do and it still does then it's fair to say for the most part it will be yourself that's wrong.

White spirit thinned enamel paint can be sprayed but it's long drying time compared to cellulose based products makes for a very difficult to apply process fraught with overload potential and subsequent runs/slumping. Another factor to consider with slow drying is the time it has to creep under any masking used.

There is a considerable range of products to chose from but personally I find 'cellulose based products' are far better for spraying in model form due to their rapid drying and their characteristic of bonding with the previous coat and subsequent build up.

I've had some very good results over the years but also a fair number of those heart sinking moments too to reinforce this - not a pleasant time

Regards - Tug

not done it yet31/10/2021 08:34:22
6889 forum posts
20 photos

White spirit/paint thinners/etc.

Would you use water to thin an oil based paint? Would you use oil to thin a water based paint? Thought the answer might be “No”.

The same applies to other types of paint. Chemistry is important. Simple as that.

The thinners which contain the same substance may be similar, but may not be the same. Different viscosity or boiling point may be the differing criteria. That said, substitutes can be used but perhaps with slightly less-good results or perhaps more variable results. Think here turpentine beeswax polish and the (slightly) lesser quality beeswax polish made with turpentine substitute (white spirit).

The cost per litre quoted between the pukka stuff and the cheaper product is possibly misleading. The cheap stuff is likely a different fraction. They may well be compared to the difference between a single malt and a blended whisky.

Circlip31/10/2021 09:36:03
1531 forum posts

Shouldn't have thrown unnecessary info in to the mix (?) Ajax. Just listening to Marr asking a politician a question and NOT getting the answer but a round the houses non relevant reply.

If the thinner you're using works to YOUR satisfaction, fill thi boots lad and save thi brass. ( and also your hair )

Regards Ian.

Dave Wootton31/10/2021 09:44:34
320 forum posts
69 photos

Hi Ajax

I've painted a few machines and other things with Paragon, mixture of brushing and spraying, I have only ever used white spirit for thinning, and it has come out fine. some have been done for years and still look good with no peeling or flaking.

Theres a picture in my album of a Colchester Bantam I sprayed a few years ago  ( I can't work out how to add it!) this was satin finish Paragon in the correct colours, using a cheapo spray gun and little skill!

I'm going to use Paragon for the chassis of my latest locomotive after disappointment with one of the specialist model paints.

The white spirit was just ordinary DIY store stuff, I do degrease very carefully before painting.Screwfix water base degreaser is very cheap and effective, followed by panel wipe.

Theres also a picture of my Kennet which was sprayed with paragon gloss over Halfrauds etch primer.

Dave

Do I hold the record for the most edits!!!!

Edited By Dave Wootton on 31/10/2021 09:46:43

Edited By Dave Wootton on 31/10/2021 09:48:09

Edited By Dave Wootton on 31/10/2021 09:50:01

Edited By Dave Wootton on 31/10/2021 09:53:52

SillyOldDuffer31/10/2021 10:28:58
Moderator
8906 forum posts
1999 photos

Cellulose Thinners and White Spirit aren't compatible solvents, so don't muddle them up. Cellulose Thinners dissolve Cellulose Paints, and White Spirit dissolve Oil-based paints.

Whether White Spirit the same as PT8 is hard to say. I don't suppose anyone on the Forum has the facilities or insider knowledge needed to find out.

Possibly the manufacturer slapped a fancy label on ordinary commercial White Spirit and is ripping off the customer. Happens a lot with Fashionable Clothes and footwear, Car Parts, electronics and consumables. They catch customers who equate brand-names and reassuringly expensive prices with quality. If only life were so simple!

Or PT8 has been carefully formulated by expert chemists to match whatever they know to be in Paragon Paints. Quite likely because paint done properly is high-tech and for best results it's necessary to follow the instructions.

White Spirit isn't a single substance, rather it's a Trade term broadly referring to any of several different mixtures of low-boiling point oils. The exact mix would change how effective the liquid was as a solvent on a particular paint. Conceivably PT8 genuinely outperforms ordinary White Spirit. The difference is likely to show up when used as a spray thinner rather than when cleaning up, where the cheap alternative is probably effective.

The only way to find out at home is by comparing the results of many careful experiments. Not easy because much depends on the environment and it might take years for problems to show up.

So I'd use the recommended product if I were spray painting a critical or difficult to fix job like the inside of an aircraft wing, and would take the risk splashing ordinary White Spirit on less demanding paint jobs. The paint on an indoor model is much less stressed than that on the Forth Bridge!

As always, no tears please if a cheapskate bodge goes wrong!

smiley

Dave

Edited By SillyOldDuffer on 31/10/2021 10:29:46

not done it yet31/10/2021 10:31:02
6889 forum posts
20 photos

Dave,

You could easily reduce those ‘edits’ shown by deleting them when you edit. That would only leave one showing.

Andrew Tinsley31/10/2021 10:31:22
1615 forum posts

Tried thinning Paragon paint with white spirit last night and painted a smooth cast iron surface. Results this morning are first class.

This plus Ajax and Dave Wooten's long term experience, convinces me that White Spirit is just as good as Paragon's expensive PT8 thinners.

The naysayers are welcome to buy the expensive product, I for one will use White Spirit.

Andrew.

Nigel McBurney 131/10/2021 11:09:15
avatar
1004 forum posts
3 photos

I bought a tin of paragon paint for my Ruston Hornsby stationary engine a year ago,a fair bit of paint had been used before the last part to paint was the sheetmetal crank guard,the paint by this time was a thicker so I thinned it with white spirit,it seemed ok but when used it I got a lot of heavy brush marks,so rubbed down,changed brush and had another try ,same result a lot of brush marks, it took a long time to find a water cooling tank,which required painting,so I bought a new tin of paragon paint,no thinning needed and the results were far better ,my thoughts are follow the instructions and do not use white spirit,though I must admit the paragon thinners is expensive and has a short life..I also find that oil based enamel paints are difficult to find and take ages to dry hard,on black trolley iron work and cast wheels I now used aerosol blackpaint at least it drys quickly.I now tend to restore and paint an engine in the summer and autumn,of one year,let the paint harden until the following spring then start and run it.

Ramon Wilson31/10/2021 11:41:29
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1401 forum posts
448 photos

As a 'naysayer' I'd just like to point out that using anything but the recommended thinner is, like most things, down to the individual choice. Cost is also down to choice - if you want to be a cheapskate and 'save brass' then that's fine too.

The original poster asked for advice - lot's given so far so it's down to him what he chooses to listen to and what he chooses to ignore.

Like him I have often questioned the manufacturers recommendation to use the brand thinner. It's an advice often ignored and often - more often than not - with a successful outcome. However it's when it goes wrong that it's a bit too late once the reaction sets in.

Paints have moved on a tad since the tins of dope and Humbrol enamel of our youth - run the risk of a spoilt job or hedge your bets for the best you can achieve is the basic choice - and bear in mind too there's a huge difference in obtaining a good finish between using a brush and spray gun.

Tug

Hillclimber31/10/2021 12:10:27
avatar
208 forum posts
52 photos

What's the difference?

I have thinned Paragon enamel with white spirit perfectly successfully for immediate application by brush from a cup. But have found that thinning a greater quantity in a tin, sees the white spirit separate back out over time - leaving a goopy enamel below.

So my advice is to use PT8 if you're adding it into the tin and expect to put its content back on the shelf.

The other thing I'll say is that the Paragon chaps genuinely know their paint. I called up when I had a problem with enamel 'matting' and they talked me right through it after discussion with the paint department. I simply had not stirred it to the point of pain (is that why it's called paint?). Total result, and lovely people.

Cheers, Colin

Mike Poole31/10/2021 12:30:05
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Moderator
3383 forum posts
77 photos

I do not know whether other solvents may be compatible but the long term performance can only be assessed by seeing what happens in the future. The suspicion that we are paying a premium price for a common product does linger but considering the work required to paint something in the first place and the wretched business of stripping and repainting if the non recommended product fails to perform I think I would go with the recommended product and suffer the cost. Data sheets seem to be carefully written to not give any proprietary secrets away even if the secret is that it is a bog standard material. It would be annoying to find that some time in the future the stability of the paint was compromised by an unsuitable solvent and dulling or cracking or never reaching full hardness occur.

Mike

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