Polyurethane Varnish

[Colin BishopModerator @colinbishop34627]

As some people on here will be aware, I am a great fan of traditional polyurethane varnish which can be used over most finishes without problems and is very durable. Several firms make it but it is less easy to obtain than it used to be as the main outlets often only stock the acrylic quick dry type.

Earlier today whilst in a traditional hardware shop in Emsworth, Hants, I came across these handy sized 125ml tins from Blackfriar. They also do a gloss as well. They are not cheap on the face of it at £4.25 each (although a lot cheaper pro rata than Humbrol tinlets) but I thought they were worth it!

Colin

 

Edited By Colin Bishop, Website Editor on 01/10/2015 16:21:14

[Colin BishopModerator @colinbishop34627]

Handy size tins

[Dave MilbournParticipant @davemilbourn48782]

Well spotted, Admiral! Now all I need is to find a local example of the aformentioned traditional hardware shop.

DM

[Colin BishopModerator @colinbishop34627]

Isn't there one at the bottom of your garden Dave?

Colin

[Dave MilbournParticipant @davemilbourn48782]

Nope – the place is over-run with fairies (and an enormous holly hedge).

DM

[Colin BishopModerator @colinbishop34627]

It seems to be on sale quite cheaply here:

**LINK**

**LINK**

The bigger tins are easier to come by.

Colin

[ashley needhamParticipant @ashleyneedham69188]

Colin. I shall be looking forward to all these highly gloss varnished boats wot you will be making.

Ashley

[Colin BishopModerator @colinbishop34627]

Ashley, if you had looked at the piccy you would have noticed that the tins are Matt and Satin. Shiny boats are for Russian Oligarchs and people who build from hardboard.

Colin

[ashley needhamParticipant @ashleyneedham69188]

Colin.. Sending You a picture to disprove this…. Ashley

[Colin BishopModerator @colinbishop34627]

Thank you Ashley, very impressive. I suppose it is still secret at the moment though…

Colin

[Dodgy Geezer 1Participant @dodgygeezer1]

Posted by Colin Bishop, Website Editor on 01/10/2015 16:17:18:

…. but it is less easy to obtain than it used to be as the main outlets often only stock the acrylic quick dry type.

Type "polyurethane varnish" into EBay any you'll get 500+ hits, at a typical cost of £6-£7 per 250ml (which includes postage)…

[Colin BishopModerator @colinbishop34627]

DG, yes it is easy to get if you search but it doesn't tend to be on the shelves of the main DiY outlets (except sometimes in large very expensive tins) which is where a lot of people tend to look first. So they settle for the, in my humble opinion, quickdry type instead.

Exterior household paints also seem to be wimpy these days, the quickdry types are prone to peeling. I use a one pack yacht enamel such as Toplac which you can get in marine chandlers. It is more expensive but you can feel the difference when it goes on and it is intended to last for several years in a harsh marine environment.

Colin

[ashley needhamParticipant @ashleyneedham69188]

Colin, Thank YOU, Yes, secret. I need a weed free pond and a nice day for pics yet. Be months at this rate. I may get to try it on the ice!!

I used Wilco Yacht varnish. For those of you old enought to remember Woolworths (little joke there) will remember that on several occaisions their Winfield brand paint won "best paint of the year" award for value durability and so on. Cant remember who actually made it, but big stores would not be likely to sell duff stuff (possibly pound shop excepted). Well, I am hoping so anyway !!

Ashley

[Colin BishopModerator @colinbishop34627]

I expect the Winfield paint had lead in it Ashley!

Yacht varnish should be OK as it is specially formulated to resists UV and is slightly flexible to cope with temperature changes. You don't get quick dry yacht varnish!

I don't think it is a question of big stores selling duff paint, the rules and regs require solvents to be virtually removed these days so everyone has gone down the water based route or substantially reduced the solvent content. Only speciality paints retain the old formulations to some extent.

Not so long ago you might paint an interior door with solvent based 'Eggshell' which was hard and durable. Now you seem to only be able to get the quick dry type which appear to go on OK but six months down the line you can still easily lift the surface with a fingernail.

Colin

[Ian GardnerParticipant @iangardner62867]

I was in my local Homebase last week bemoaning the fact that you could only get 750ml tins of Ronseal Polyurethane varnish and all the the 250ml tins were the acrylic quick drying type- which I do find useful for overcoating matt Humbrol actually.

As a result of this thread I have just ordered a 250ml tin of polyurethane varnish on Ebay which I can click and collect from my local Argos or Homebase for nothing- it was about £6.

So thanks!

Ian

[Dodgy Geezer 1Participant @dodgygeezer1]

Posted by Ian Gardner on 02/10/2015 12:46:02:

……..

As a result of this thread I have just ordered a 250ml tin of polyurethane varnish on Ebay which I can click and collect from my local Argos or Homebase for nothing- it was about £6.

 

 

Almost all of my modelling material purchases – and almost all of my other purchases as well – are now made on the net. Certainly all my big purchases are. My grocery shopping is web-based and delivered to my door, and the most common country I buy something from is China.

I also can't remember when I last used cash for a purchase of any kind. One good thing about buying from abroad is that you can get items which are banned for sale in this country….

Edited By Dodgy Geezer on 02/10/2015 13:53:43

Edited By Dodgy Geezer on 02/10/2015 13:55:40

[BanjomanParticipant @banjoman]

Speaking of PU varnishes, has anybody here had any experience of the 2K variety, like for exmple this one: **LINK** ?

/Mattias

[Michael BordParticipant @michaelbord10152]

Re the matt polyurethane varnish mentioned, I'm looking for a durable varnish for the hull of the revell Flower class corvette I'm (slowly) building. I've used revell acrylic paints on the sides of the hull (airbrushed) and Halfords matt black acrylic spray paint on the bottom.

This has given a very matt finish, which looks good imho, but I think it may need a further protective clear coat over it. I'd like to preserve the matt look of the hull.

Has anyone had experience of spraying matt polyurethane varnish over acrylic paint, and if so does it dry really matt? Or are there alternative (matt) finishes to protect a model boat hull? I've used Testors Dullcote on non working models before, which does dry really matt but not sure how it would last at the pond.

I appreciate that polyurethane is dodgy stuff to spray, this would be in the garden with face mask etc.

Advice gratefully received!

Michael

[Paul TParticipant @pault84577]

Hello Michael

As a general rule of thumb it is inadvisable to mix paint types (or even different manufactures) as the chemical composition of the dissimilar products might react with each other.

In your particular case the sprayed varnish might react with the acrylic base coat and cause it to suffer from 'orange peel' (where the base coat crinkles and cracks)

I would try the spray varnish on a test piece and wait 12 hours before applying it to the entire hull.

Alternatively you could use Halfords matt lacquer spray which should be compatible with the matt black, ask someone at Halfords about the compatibility.

I hope that this waffle is of some help

Paul

[Colin BishopModerator @colinbishop34627]

As Paul saya, you need to be very careful when using different types of paint. The polyurethane will go on over the Halfords matt black OK but you will certainly need to check if it is compatible with the Revel acrylic on a test piece as Paul suggests. Why not just use the Revell clear matt acrylic for the topsides thn you will have no worries?

I think that any true matt coating is vulnerable to staining to some extent as a matt surface is inevitably more prone to showing marks than a gloss one. Most varnishes, even if billed as matt, will tend to have a very slight sheen but this does not usually matter in practice.

Colin

[Michael BordParticipant @michaelbord10152]

Thanks Paul and Colin, very useful advice, especially about paint incompatibility. I shall certainly test whatever I use (having taken a long time on mixing and spraying the topside colours and masking the bottom.

As you say Revell matt acrylic should be compatible, I'll try that, also the topsides shouldn't be getting so wet (much).

I've used Halfords gloss lacquer over Halfords gloss acrylic car paint on a launch hull and it's lasted very well, so hopefully the matt one should also be protective. Got some test pieces I used when experimenting with colours so I'll have a go with them.

If it was to be a non working model, I'd leave the finish as it is, but I feel it could do with a bit more protection. (the hull's ok as it's plastic and waterproof anyway, just to maintain the appearance.)

Thanks,

Michael

Thanks very much, don't want to spoil paint finish after all this time!!

[BanjomanParticipant @banjoman]

Michael,

I will first of all echo the advice given by Paul and Colin: always try out any unknown, new and/or multibrand combination of paints and varnishes on a piece of scrap material before applying it to your model!

As for possible varnishes, you could also have a look at the Vallejo RC Premium series (**LINK**). While it is not likely to be as strong as anything even mildly solvent based, it is intended for airbrush application (but can also be brushed on with good results), is water based so does not pong and can therefore be applied indoors without any problems (although one should of course still wear a mask if airbrushing to avoid inhaling the particles), and comes in gloss, satin and matt. And, given that this series of paints has primarily been developed for use on r/c car bodies, I'm inclined to believe their claim that it is tougher than corresponding model varnishes for static modelling.

In the UK you can get these paints from amongst others Amazon (**LINK**) or Everything Airbrush (**LINK**).

To give an idea of how matt they come out, here are two pictiures of my recent Puffer build, the first before varnishing the hull

and then one where RC Premium satin varnish has been applied

Although there are some differences in how the two pictures are lit, I think you can still see that already the satin version of the varnish cuts some of the paint brilliance and gives a fairly matt final appearance.

/Mattias

Edited By Banjoman on 18/10/2015 08:47:39

Edited By Banjoman on 18/10/2015 08:48:13

Edited By Banjoman on 18/10/2015 08:49:46

[Michael BordParticipant @michaelbord10152]

Hi Banjoman,

that's a really nice puffer, (as an aside, the plating and rivets look good). And the satin varnish finish looks realistic for that type of ship. Haven't come across Vallejo RC Premium before, tried various makes and types of paint over the years for different static models. I've got a local model shop that does r/c cars etc and they may have some so I'll try them tomorrow. (Then mail order if not). Got a small tug model coming along that it could be used on as well. I've got plenty of spare plasticard to try paint/varnish on first.

The working model boats I've made recently have been launches etc. where I've looked at them as "small full sized boats" as it were, where making the hulls watertight and having a durable finish was the important thing. However, the corvette is becoming more of a "display model that can be sailed" as I've ended up adding more detail than originally intended. Therefore I'd like to preserve the paint work as much as possible.

What scale is your puffer, by the way?

[Michael BordParticipant @michaelbord10152]

Since my last post I looked at Amazon and bought a bottle of the Vallejo RC Premium matt varnish £3.96 with free postage, the spec sounds a very tough finish for working models so I'll report back later. I'll try and post a pic.

[BanjomanParticipant @banjoman]

Hello Michael,

And thank you ever so much for your kind comments on the puffer! I cannot take any credit whatsoever for the rivets and plating, as these came ready-moulded on the hull; the model is based on the Mountfleet Models Highlander kit, although I've scratch built parts of the superstructure, and replaced a number of the original, white metal fittings.

The scale is 1:24, and should you be interested in a cloder look, there's a build thread on the forum here: **LINK**

As that thread will tell you, the greatest part of the apint work was done using Vallejo RC Premium paints, which I found very good indeed! They are water based acrylics, so will never be as tough as for example enamels, but I really enjoyed working with them! As with any type of paint, there are advantages and disadvantages.

They airbrush very well, and, with a larger needle (I mainly used a 0.6, but 0.4 would do, too) didn't even have to be diluted but could be applied straight out of the bottle.

The range of colours available is limited, but they mix together beautifully, and with the help of a set of paint scales (accurate to 0.1 of a gram) I was able to consistently mix all the shades I needed.

They also have good self-levelling properties, and will thus brush on rather well, too.

The pigments are very powerful indeed, and the coverage is thus excellent. In particular the black is outstanding — I think I used maybe 20 ml (!) to fully paint the upper bulwarks!

Please note (also for the varnishes) that as these are acrylic paints, they will dry from the outside in, i.e. they will feel quite dry on the surface and can be handled no problem, but won't necessaily have really and truly cured. If you look halfway down page 4 of my thread (**LINK**), you will see that I ran into problems with my varnish on account of not leaving it to cure for at least a week before testing the model in the bathtub. Suffice it to say that, after redoing the varnish job, I did give everything plenty of time (several months in fact, which is of course much more than needed) before putting the hull in water again, and that I have not had any such troubles since.

As a final point, I think you need to, as it were, somewhat dilute the spec claims of toughness — or in other words to factor in the usual manufacturer selfpraise. These paints and varnishes are indeed quite tough, and I have certainly found them suitable for working models, but I wouldn't claim for them to be quite as indestructible as Vallejo implies.

And of course: please test off the model first, both for compatibility and for a to you satisfactory degree (neither too glossy nor too dull) of mattness!

/Mattias

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