Deans Marine

Hints and Tips => Glues & Paint => Topic started by: kit on 13 January 2015, 14:12:56

Title: Humbrol matt spray varnish
Post by: kit on 13 January 2015, 14:12:56
Just thought that I'd give a heads up to others about a little problem that I had with my Zulu....

I brush painted the kit with a combination of humbrol and revell enamel, everything worked out fine and there was no reaction between the different manufacturers.  I then sprayed it with Humbrol matt enamel varnish from a spray can to smooth over the finish and get rid of the brush marks; of which there were many.... 

It came out with a slightly satin finish but I wasn't too worried about that, as far as I can remember warships don't have a flat matt finish anyway.  This was in August 2014.

Come October I noticed some changes in the colour scheme.  The deck was now greeny brown, the superstructure and hull were greyey brown and the white bits were just brown.  The effect was exactly the same where I had used humbrol and revell paint so that wasn't the problem.  The only bit that wasn't affected was the focsle where I had applied a really thick layer of varnish that took about three hours to even start to dry; lots of brush marks to cover!

Doing some more research on the internet I found out that browning can be a problem with varnishes.  I guess that the more experienced of us are fully aware of the problem so just a warning for others.  Having to repaint the model top to bottom over Christmas was something of a pain!

Cheers

Kit   

Title: Re: Humbrol matt spray varnish
Post by: minerva on 13 January 2015, 19:33:25
I have always used Halfords Acrylic car paints (spray cans)as recommended in Deans instructions.
Ford Polar Grey (ships side grey)  Matt black for boot topping and red primer for anti fouling
and FX. I prime first using Halfords matt grey. For white areas I use Ford Diamond white.
No problems at all but it is rather expensive.
Title: Re: Humbrol matt spray varnish
Post by: Troy Tempest on 14 January 2015, 09:22:13
Instead of regular varnish a tip I've picked up from scale modelling is to use Johnson's Klear  Its actually floor polish but makes an excellent seal and dries to a Satin finish. Its also useful to apply prior to any decals to avoid silvering and then as a top coat to seal them on.
Ever since I had some yellowing from Humbrol varnish Ive used this and no after effects seen
However as always I would advise testing first just in case there is a reaction with whatever paint is being used
Works fine on Halfords rattle cans however, in support of Minerva's post I use the same making sure i select the plastic primers as they also sell the same colours as metal primers
Title: Re: Humbrol matt spray varnish
Post by: minerva on 14 January 2015, 09:46:37
Regarding Johnson's klear, I have a bottle here (it's last for ages).
I always use it to dip clear plastic parts for glazing in, allow to dry and then
these can be fixed in place using cyno, the Klear prevents misting of the glazed
area. (ref 4.5" gun directors from shapeways and bridge glazing )
Title: Re: Humbrol matt spray varnish
Post by: Mark on 14 January 2015, 11:44:16
Humbrol varnish has a Polyurethane base and always goes yellow no matter what you do. I always give a model a waft over with acrylic satin varnish before the final glazing and rigging, just to seal all the surfaces. On the hull I will give a couple of coats if its a working model, just so I can get it clean easily after its been afloat.
Title: Re: Humbrol matt spray varnish
Post by: colin on 14 January 2015, 12:42:09
with you all the way Mark...  ^^^
i use a different Satin Varnish, from a DIY store in Germany, but they have gone bust so will have to look for another supply..

the yellowing effect is what i am after..!
Title: Re: Humbrol matt spray varnish
Post by: kit on 15 January 2015, 11:19:14
Troy/Minerva

Interesting on the Johnson's Klear - I only ever used it on shoes before...  I used Humbrol clearfix on glazing but it's awfully gloopy so I'll give the Klear and superglue a shot.  And on the hull - I'll post to let others know if it works on and under under enamel.  Don't like acrylic but that's just me.

Mark

Does the varnish work on enamel?  Some do, some don't.  If it does, which one is it?

Title: Re: Humbrol matt spray varnish
Post by: radio joe on 15 January 2015, 12:50:50
I know a lot of people spray varnish over the finished model, and of course each to there own every time, but I have never understood the need to do this, all of my boats are painted with acrylics they have been in water many times and been toted around many exhibitions the oldest one is about 4 years old and they all look the same as the day I finished them ::DD
Title: Re: Humbrol matt spray varnish
Post by: Troy Tempest on 15 January 2015, 13:55:08
Kit
Many modellers have been using Klear to improve the look of transparency parts e.g. cockpit canopies on a/c
If you dip the part briefly in Klear, allow the excess to run off and then allow to air dry it makes clear parts look clearer!
NB make sure you dry the part under cover e.g. a plastic tub of some sort otherwise the dipped object becomes a dust magnet!
Title: Re: Humbrol matt spray varnish
Post by: kit on 15 January 2015, 19:17:49
Thanks Troy - I'll give it a shot and see what happens

Joe - it worked a treat covering up some yucky brush marks a few years ago and I guess it just became a habit.  My experience (limited) is that enamel holds dirt more easily and varnish solves that problem - as long as you like yellow!
Title: Re: Humbrol matt spray varnish
Post by: radio joe on 15 January 2015, 19:32:42
Hi Kit
Yes I'd agree with you there, that's why I never use enamel paint.
Joe
Title: Re: Humbrol matt spray varnish
Post by: kit on 24 January 2015, 20:28:58
Aaaaargh - Johnson's Klear discontinued and no longer available.   

Apparently the Pledge 'successor' is nowhere near as good - any suggestions?
Title: Re: Humbrol matt spray varnish
Post by: Troy Tempest on 25 January 2015, 11:23:02
Sorry Kit I wasn't aware of that
It lasts for ages so my old bottle hasn't needed replacing
Ive looked at some other websites and the new version Pledge seems to get some good write-ups even if it isn't as good as Klear
Why not try some on a test section and wait and see what the results look like?
I se some people cashed in on the demise of Klear by purchasing stocks and are now selling it on eBay!
Title: Re: Humbrol matt spray varnish
Post by: derekwatson45 on 26 February 2015, 13:49:45
Interesting article. I have had lots of issues with varnish and ended up having to do a complete repaint. never thought about the halfords rattle can route. Think I will give this a go with my new projects
Title: Re: Humbrol matt spray varnish
Post by: kit on 07 March 2015, 05:46:13
OK,  I've done my research so here are the results just in case anyone is interested.

Just as a base point I use Humbrol and Revell enamels, I have mixed and matched between the two without any problems.  I don't like acrylics but that's just personal choice.

As mentioned above, Johnson's Klear has been discontinued and is no longer available except for stupid money on eBay.  However, Humbrol now make their own version and I bought a pot (125cc) for ?4.99 so not exactly cheap. 

I also tested the Humbrol Satincote and Mattcote which are heavily plugged as non yellowing so in the end I just went for them.

So, test results.  I only used a brush:

Humbrol Klear - goes on nice and easy, quick drying, nothing in the way of brush marks as its really runny.  There were no reactions when applied over either Humbrol or Revell enamels and could be overpainted with both so a plus there given the inevitable damage that occurs over time on a working boat. 

Cyano can also be applied on top, or at least the one I use can (Admiralty).  The cyano and the klear seem to react with each other to start with but then they settle down and bond but you have to hold the components together for longer than usual.

I tried to use this glue over a Humbrol acrylic rattle can and the two just reacted with each other and wouldn't bond - guess there is a clue with the name!

Humbrol Satin/mattcote - these are oil based so work fine over or under enamel, not sure about acrylic.  I couldn't get the satincote to brush satisfactorily over large areas without brush marks.  It's also not very good at covering up the underlying brush marks which was the whole point in varnishing to start with.

Mattcote worked well, albeit that there are still some minor glazing issues.  I suppose this is inevitable on a large model when using a brush but the effect is more pronounced on dark colours (deck green) than light (ship side grey). 

It requires a ridiculous amount of stirring to properly mix the matting agent - I used a dremmell on a fairly swift setting for about 15 minutes and there was still stuff left at the bottom of the pot.  If you don't mix it properly the matting agent will dry outside the solution leaving a white powdery effect.  It can be cleared up be repainting with glosscote and then re matting but that's all a bit of a pain.

I found I got best results with three or four thin coats and brushing each bit back and forth until the brush just started to drag as the varnish dried.

In the end I didn't use Klear as I don't like my ships to have a satin/gloss finish.  This is just me.  I know warships have a satin/gloss finish but I have been building them matt for so long it just doesn't look right so this is personal preference.  I now that Klear dries satin on the first coat but I invariably wind up applying two or three to cover up glue marks and Klear gets progressively more gloss the more coats you apply.   

Anyway, hope this helps anyone using enamels - pretty irrelevant for the rattle can users!  But brushing enamel means I can paint all year round.  The shed is a fridge at the minute and I can just see She Who Must be Obeyed reaction if I turn the dining room into a spray shop....

Cheers

Kit
Title: Re: Humbrol matt spray varnish
Post by: kit on 07 March 2015, 13:32:25
Oh yes, knew I'd forgotten something - I diluted the mattcote down by about 20% with thinners which made it easier to apply and dry out a bit faster
Title: Re: Humbrol matt spray varnish
Post by: colin on 08 March 2015, 07:18:31
a very intersting read, thanks very much for this Information  ^^^
Title: Re: Humbrol matt spray varnish
Post by: minerva on 21 March 2015, 11:57:54
Johnson's Klear IS available on e bay.
21 / March 2015.