What type of varnish to use on buildings

Hi
I am starting to add more structures to the line using various materials (concrete, wood, resin) and painting them using a mixture of Halfords car spray paints, Humbrol enamel and masonry type paint pots.  Most of the buildings will be left out all year. 
I seem to remember reading somewhere about adding a coat of varnish to the finished items to protect them.
Unfortunately I have found problems with the two building that have been out since last year.  In that the varnish has gone yellow/brown and is peeling off.
I was wondering if it is best to just leave off the varnish stage or if anyone can suggest a more suitable varnish to use?   (cannot find the tin of varnish spray I used last year so dont know the make sorry)
 
Thanks  Colin

I'm no expert but I remember reading somewhere that water-based varnish should be used on water-based paints (eg acrylics) and oil-based varnishes on oil-based paints (eg enamels). Maybe that's why it peeled off. I've given my buildings a spray of Plastikote acrylic varnish as I used a water-based exterior paint on them. They've not yet been out a full year so no idea how they will survive.



Rik

What a brilliant question

Hi, 

I use Johnsons Klear - which is intended for kitchen floors. Its an acrylic vanish, though the new version is said to have a slight brownish cast - I have not seen it, as the new bottles are opaque - the old ones were clear.

I tend to use acrylic paint but some buildings are enamel and I have not had it peel. The building were almost covered in snow last winter with no damage or peelin.

Tesco don't sell it but Morrisons do, just be aware of alledged brown cast.  That should be OK with wooden buil;dings or red oxide colours anyway!

 

Good Evening All, don't know if it's any help but i have coated my buildings with plasticote varnish also,over enamel and acrylics and emulsion, been outside for up to 2 years now, no flaking or discolouration up to yet.Regards Pete.

mine is garden fence paint on my wooden building as trestlles,kitbashing it,shed,etc.....i had a heavy snowfall 4 times last dec and jan.....no problem.....every year i re-stain it as i want to.......

aslo use wilkoson outdoor varish tin tht i varished on signsetc...,,2 hours to dry it...exellent but bit of shiny....lol....but worth it............mine satin not gloss...

Thanks, will have a look around for those suggested varnishes may try a few different ones on test pieces and see which stand the test of time.  If I use Johnsons klear will see if it does leave a slight brown tint and how much.
One good point to come out of all this is that repainting the two building I find I am getting better at this dry brushing lark.
 
Regards Colin

A bit of dry brushing is very theraputic I find.................. my wants a simple these days

I like the plasticote coat idea, their paint range is good and covers well

EDarlier I mentioned Johnsons Klear had a slight brownish cast but could not verify it.
 
Since then Johnson's have changed the packaging and I have also bought one. Yes there is a vert slight cast wehen l;ooked at in the white container, but when it is applied the cast cannot be seen, having tried it on a mid grey background.

It is £3.05 per container by the way and now has a new smell - before there was none. It seems to be the same but is said to have a 'wax'  in it. It can be removed if required by a weak ammonia & water solution.

Yours Peter B.