Lead Adventure Forum

Other Stuff => Workbench => Topic started by: Argonor on October 08, 2015, 09:39:11 PM

Title: MDF -. Does it Need Primer?
Post by: Argonor on October 08, 2015, 09:39:11 PM
I just recently started collecting laser-cut mdf-buildings from Sarissa (Old West, for now), and am rather pleased with the kits, and I think the raw mdf will be ok for the first couple of games.

Obviously, though, the buildings are going to need some paint along the way, so I would like to know if they need to be primed before painting or if the mdf takes paint well enough directly to the surface?

I'll probably be using acrylic craft paint, thinned to a suitable consistency.
Title: Re: MDF -. Does it Need Primer?
Post by: Eric the Shed on October 08, 2015, 09:43:21 PM
Primer yes, but thinned paint good
Title: Re: MDF -. Does it Need Primer?
Post by: Argonor on October 08, 2015, 09:47:00 PM
Primer yes, but thinned paint good

So, thinned paint as primer, instead of expensive spray?
Title: Re: MDF -. Does it Need Primer?
Post by: Michi on October 08, 2015, 09:54:41 PM
I didnīt prime these Sarissa buildings:


(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale231.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale228.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale233.jpg)

First in the row is the telegraph and post office which is also home of the local newspaper with its own print shop.
(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale244.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale266.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale243.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale242.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale241.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale240.jpg)

The next building is strictly for male visitors, even if it has a lot of female staff.
(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale249.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale261.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale257.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale256.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale255.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale254.jpg)

The floors are fully accessible for gaming inside the buildings:
(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale260.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale236.jpg)

Then comes a hotel.
(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale263.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale253.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale252.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale251.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale250.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale238.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale237.jpg)


There is another two-story building which gives shelter to the finest clothes in the west. Ladies fashion upstairs, gents first floor please:
(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale248.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale262.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale247.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale239.jpg)

Last but not least is a rather useful and certainly prospering enterprise in wild west times.
(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale235.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale264.jpg)

(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale234.jpg)

I will try to cramp some furniture in there later.
(http://i286.photobucket.com/albums/ll111/wamasaka/Mini2011/MiniaturenfotosOriginale259.jpg)
Title: Re: MDF -. Does it Need Primer?
Post by: Argonor on October 08, 2015, 10:17:41 PM
Painting goes a long way to make the buildings look better by coverning the un-attractive burn marks from the laser.

It seems you added window glass? And the roof shingles look different than those on my buildings?

I am going to get furniture and props, first, then later slap some paint on.
Title: Re: MDF -. Does it Need Primer?
Post by: Connectamabob on October 09, 2015, 12:32:48 AM
MDF, compact as it is, is still starchy and porous, so I wouldn't think it'd need primer for adhesion reasons. Maybe to get a unifying base color, but I wouldn't expect there'd be any trouble with paint lifting or flaking on bare MDF.

If one did want to prime it, it seems like a perfect job for gesso, IMO.


Title: Re: MDF -. Does it Need Primer?
Post by: Ragnar on October 09, 2015, 01:29:33 AM
Michi, they look fantastic!
Title: Re: MDF -. Does it Need Primer?
Post by: Ray Rivers on October 09, 2015, 02:20:00 AM
Never thought MDF could come out so well...  :o

Nice job, Michi. I assume the lettering is freehand.  :-*
Title: Re: MDF -. Does it Need Primer?
Post by: exploding youth on October 09, 2015, 04:33:05 AM
The MDF is very thirsty, so priming helps achieve an even coat of paint. I'd recommend priming for sure.

Those buildings above look incredible!
Title: Re: MDF -. Does it Need Primer?
Post by: Eric the Shed on October 09, 2015, 04:55:50 AM
So, thinned paint as primer, instead of expensive spray?

Yes...especially if you want to keep all the etched detail
Title: Re: MDF -. Does it Need Primer?
Post by: OSHIROmodels on October 09, 2015, 07:01:17 AM
The cut edge of the MDF soaks paint up more than the flat normal surface but the burnt lasered surface goes some way to help seal it.

I would recommend priming as it will also help to keep the noxious fumes at bay  :)

A rattle can of automotive primer would do the trick.

cheers

James
Title: Re: MDF -. Does it Need Primer?
Post by: ancientsociety on October 09, 2015, 08:37:10 PM


Remember, you prime objects to give paint a ground to stick to. The texture and porousness of MDF already act as sufficient ground for painting, so you don't need to prime it.
Title: Re: MDF -. Does it Need Primer?
Post by: NurgleHH on October 19, 2015, 05:56:38 PM
For My boards I used Mdf-primer. It worked well and was Not expensive.
Title: Re: MDF -. Does it Need Primer?
Post by: Dr. Zombie on October 19, 2015, 06:07:00 PM
MDF drinks up paint like a sponge. I have "primed" my MDF buildings with hairspray as it is very much cheaper than spray paint.  And then painted with watered down paint.
Title: Re: MDF -. Does it Need Primer?
Post by: Malebolgia on October 19, 2015, 06:08:03 PM
Are we talking MDF or HDF? Makes a big difference. The HDF stuff soaks way less paint than MDF. Even then, I always prime the stuff.
Title: Re: MDF -. Does it Need Primer?
Post by: obsidian3d on October 19, 2015, 06:47:04 PM
Wow I'm working my way through a western town right now and I would LOVE to hear some tips on how you get such a great look Michi!
Title: Re: MDF -. Does it Need Primer?
Post by: Argonor on October 19, 2015, 07:54:47 PM
Are we talking MDF or HDF? Makes a big difference. The HDF stuff soaks way less paint than MDF. Even then, I always prime the stuff.

Says MDF on the tin.
Title: Re: MDF -. Does it Need Primer?
Post by: bishop odo on October 20, 2015, 04:15:53 PM
MDF is venerable to moisture, mainly on cut edges should be sealed.  What happens is the edge raises just a little making a almost bur that has to be sanded or not.  Once you paint it or prime it that seals it, and that's the most important part, but it seems to me, that after spending the money on all that laser cut goodness, trying to save pennies on the primer steps is a little foolish. 
Title: Re: MDF -. Does it Need Primer?
Post by: Argonor on October 20, 2015, 06:59:32 PM
Not trying to save money, just not wanting to obscure detail with a perhaps unnecessary layer of paint.

One of my friends told me that his alternate gaming group (Infinity) primed their futuristic mdf with an airbrush, and that the paint seemed to stay out of the fine laser-cut lines - maybe that would also happen with a spray?
Title: Re: MDF -. Does it Need Primer?
Post by: Malebolgia on October 20, 2015, 07:22:59 PM
This post by Antenociti is also a good read on MDF and HDF:

http://www.data-sphere.net/forum/viewtopic.php?f=13&t=782&start=0#p9113

*edit*

And this too:

http://infinitytheforums.com/forum/topic/14355-painting-mdf-terrain/
Title: Re: MDF -. Does it Need Primer?
Post by: Argonor on October 20, 2015, 08:07:14 PM
MDF drinks up paint like a sponge. I have "primed" my MDF buildings with hairspray as it is very much cheaper than spray paint.  And then painted with watered down paint.

I think I may try that approach - in the summer half of the year I am playing games i n the garage attic, and the air can become a bit humid up there, as it is not insulated, and outside air has some access.
Title: Re: MDF -. Does it Need Primer?
Post by: Michi on October 20, 2015, 09:39:52 PM
Wow I'm working my way through a western town right now and I would LOVE to hear some tips on how you get such a great look Michi!

Itīs rather dry and thick acrylic paint slapped on the bare MDF with rough brush strokes in three layers of increasingly lighter tones and a black wash followed by a leather brown wash applied after drying.
Title: Re: MDF -. Does it Need Primer?
Post by: Major_Gilbear on October 21, 2015, 08:31:19 AM
HDF/MDF + Moisture = bad.

If you use a hairspray to seal the stuff before painting, just be sure that the finished product isn't kept anywhere damp or humid as most hairspray is (for obvious reasons) water-soluble.

I would say that a decent quality spray primer or a decent primer coat laid on with an airbrush is a good idea just to seal the stuff and provide a good surface for the paint to stick to.

I would also avoid using any paints that are very wet directly onto the bare MDF, as the high moisture content could cause the cut edges to swell.

Whilst I agree that primer is used on models to assist with the adhesion of your paint to them, there are a few of other reasons to consider doing the same for MDF:

1) Automotive spray primers have a lot of solvent in them, and this helps them (and subsequent paint coats) to stick to the model even if the surface is very smooth or has a small amount of grease (maybe from very light handling) on it. You can wash a model to minimise this and improve the primer's adhesion, but you cannot wash MDF! After assembly, it may have some grease from your hands on it (especially if it was a tough build!), and the primer will help to avoid any thin coats of paint from leaving uneven areas.

2) The primer seals porous surfaces, and has a little tooth to encourage even coverage of subsequent paint coats. For MDF, I think these are both good reasons to prime.

3) The primer is pretty tough, and (together with a varnish at the end) will assist in salient parts of the models from getting the paint rubbed or scuffed too easily.

As long as you use thin coats (even multiple thin coats will a full period of drying between coats), I would argue that there are more (albeit somewhat marginal) benefits to using a primer than not using one.

Personally, I prime everything regardless. :)
Title: Re: MDF -. Does it Need Primer?
Post by: Connectamabob on October 25, 2015, 01:41:32 AM
One of my friends told me that his alternate gaming group (Infinity) primed their futuristic mdf with an airbrush, and that the paint seemed to stay out of the fine laser-cut lines - maybe that would also happen with a spray?

A major benefit of using an airbrush is you get a much finer and more controllable spray than with a rattlecan. A big reason why I started ABing (and the biggest reason I'd recommend one to gaming modelers) is because it eliminates common rattlecan issues like the sandy texture you see so often in close-up pics, or not being able to hit crevices without overgobbing the high points.

Rattlecan will get you primed enough for paint adhesion, but to get a full sealing coat inside the crevices without going too thick on the surrounding highs/flats will be more of a challenge.

However, if your friend is saying that the AB wasn't getting paint inside the engraved lines at all, as opposed to not overfilling them, then they aren't using the AB correctly. Probably just spraying it in big general passes like you would with a rattlecan. That'll get you a nice coat without texturing, but it won't put paint in crevices any better than a rattlecan would. Should be obvious why. What an AB lets you do is drop paint volume and get in close so you can target the spray right into the engraved lines without overspraying the rest. If they aren't doing that, then they're being lazy, not honest.
Title: Re: MDF -. Does it Need Primer?
Post by: The_Beast on October 26, 2015, 06:18:19 PM
Remember, you prime objects to give paint a ground to stick to. The texture and porousness of MDF already act as sufficient ground for painting, so you don't need to prime it.

A major reason for priming, yes.

But, as mentioned, MDF's porousness SOAKS paint in. Is it sufficient to do many very thin coats of base/primer to build up that seal?

'Wet' MDF can lose structural integrity as well; isn't that another reason to try to seal before 'laying it on thick?'

Doug
Title: Re: MDF -. Does it Need Primer?
Post by: Eric the Shed on October 27, 2015, 07:47:18 AM
you can always seal with pva glue