What to paint a wood kit with?

Model Railroader General Discussion (Model Railroader)
1

I’ve asked this elsewhere, too, where I saw a discussion on a different forum a while ago, but I’m getting answers that don’t seem fully commital, so I’m back on the home rails, as it were, with my question.

I have several craftsman structure kits – Campbell, Durango Press – with thin wood walls. I want to paint them before I assemble them, but I’ve often heard that acrylic paints, being water-based, will warp the wood. I’ve heard I should use lacquer-based paint instead. I’ve heard I can safely use acrylic if I seal the wood first with an acrylic sealant. I’ve heard that it’s okay to let the wood warp before assembly because I’ll clamp it down anyway during the build. I’ve heard that enamel paints (Testors) will work fine, maybe.

I’d like to find something approaching more of a consensus – I think every man jack of you has built craftsman wood kits before. What paints, sealants, thinners, concoctions, tinctures, witches’ brews or other methods do you use to make sure the walls don’t warp? If any two of you agree on something that works reliably, I may follow suit.

Thanks in advance,

-Matt

2

My favorite pre-assembly primer* for wood is Krylon spray primer. Usually the gray, sometimes the oxide red and sometimes the white. The Krylon sands nicely if you have any “fuzzies” in the wood adter spraying.

Two very light coats is preferable to one heavier coat. Some assemblies such as window mulions are then painted in the finish color by hand or airbrush before assembly.

Rustoleum applies too thick and heavy IMHO. For very detailed parts I prefer the very fine gray or white Tamiya paints.

I do both sides of bare wood and, of course, only one side of the peel-n-stick stuff.

Good Luck, Ed

  • not the heavy-bodied automotive primer
3

I like a thin stain of India Ink in alcohol, applied to both sides. I’ve also had success with thinned down water-based acrylics. Multiple thin coats will serve you better than putting it on too thick.

4

Hi Matt,

I think that adding bracing to the backs of the walls before priming them is cruicial to prevent warping. Most kits will come with bracing, and you can add additional bracing if you feel the need. Don’t forget to brace the roof panels too. If you are going to detail the interior then you might want to give some thought to the placement of the bracing so it isn’t too obvious.

I use a couple of coats of automotive primer to seal the walls and details. I would suggest supporting the walls etc. on some sort of thin risers so they don’t get stuck to the surface of the spray booth as the paint dries.

As Ed suggested, painting the detail parts before assembly will give you much better deliniation between colours. This includes things like corner posts and fascia as well as the windows and doors.

One trick is to leave the smaller parts on the sprue so they are easier to handle when painting. Also, several coats are often required to get full coverage, unless you want a faded finish.

I generally use Polly Scale paints, but many people recommend using craft paints.

You might find these suggestions from Blair Line helpful:

https://www.blairline.com/howto/

Bar Mills has some excellent information as well. Scroll down to the videos:

https://barmillsmodels.com/

Have fun!!

Cheers!!

Dave

5

I think everyone has a different technique sometimes several. One thing to note acrylics cause the wood to draw up towards the side that is painted. Painting both sides equalizes this. You can also weight with a book which will flatten the wood well. Some kits work better to brace first then paint others don’t do this as well. Bracing regardless of application before or after painting is necessary to strengthen a kit over the long run especially if the layout room gets humid.

I generally use craft acrylics for wood kits. For staining strip wood I use varithane stain markers.

Jim

6

If you want the real skinny, it all depends. The real thing to make a good wood building kit is bracing, lots of it. I have never painted both sides and I have some very old buildings now but I have always braced them well. Remember you don’t need a lot of paint, esspecialy in HO. Some people apply too much paint and basicaly soak the wood and if it is water based or other, that can lead to a mess.

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Thanks for these reports, guys, and the video links.

Those of you who say you use spray primer like Krylon gray, do you do this even when the wood has some scribing on it, such as for clapboard siding? Doesn’t it obliterate the detail? Or did someone already address that?

And for extra bracing, would you use square 1/8" or 1/4" strip wood? (Interiors are not an issue.)

Anyway, thanks. I will do some testing on some extra material.

-Matt

8

I have used acrylic BUT typically with a wood structure I am aiming at a badly worn paint job effect. So it is almost a drybrush technique with taking the paint brush (or swab) and rubbing it on paper towel or piece of cardboard until minimal paint is left and then applying that to the wood. At that point there is not enough real moisture to cause meaningful swelling or warping. I also suspect that the micro plywood on laser cut kits probably resists warping more than regular die cut basswood.

Dave Nelson

9

Hi again Matt,

I would say that 1/4" square bracing would be the minimum with the possible exception of where walls are joined at 90 degrees. In that case, 1/8" would be fine for an inside corner.

Also, make sure you are using a water resistant glue like yellow carpenter’s glue. CA works as well but you have to work quickly and accurately. If you are going to just be staining or using a wash on the wood, I suggest that you do that before assembly because the stain will not penetrate into any excess glue that might be on the surface.

If you need small pieces of wood, Mount Albert Scale Lumber has a good selection:

https://www.handlaidtrack.com/fractional-stripwood

Some time ago I saw a very simple suggestion for modeling peeling paint. You start by aging the wood so that the ‘peeled’ areas will look gray. Then you apply small spots of rubber cement to the areas where you want the peeling paint effect before applying the colour coat. Once the colour coat has dried, you simply rub the rubber cement off with your finger to reveal the bare (aged) wood underneath. I have never done this personally, but it certainly sounds like a good method. There were pictures showing this method in MR several years ago.

Cheers!!

Dave

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Accually I have stained with a shoe dye alcohol base on white glued wood building and no proublem which is good. You must however removed all the wet glue you can before drying, I even uses a damp rag if it was a bad spot. I think this is because enough fibers have been left exposed but just a theory. 1/8 inch bracing is ussually fine. Frame it like you would frame a house to some extent but the bracing dose not have to be as close together.

11

Ahhhh… Wood Craftsman Kits and Scratchbuilt Structures.

I have basically four different techniques I use, depending on what I want the final finish to be…

1) New or Well Maintained Buildings:

I assemble the walls with bracing. I use 1/8" basswood as bracing and do not follow the bracing guidelines in the kit instructions. I like to add indirect lighting and interiors to some rooms, so the entire inside of my kit structures is desgned around these features.

Then I spray both sides of the walls with gray primer as Ed suggested. It does not hide wall detail at all. Before the primer is applied, I mask off the joint areas at the corners so the wood glue holds well.

I paint these buildings as normal. I usually use water based craft paints like Folk Art, Delta Ceramcoat, or Americana applied with a brush.

2) Weathered And Worn Buildings:

I assemble, brace, and prime the walls the same as in the steps above.

For painting I use the same types of water soluable craft paints, but I apply them differently. My favorite technique is to find three similar colors and apply them to the structure by dabbing them on with make-up removal sponges or small wads of paper towels.

Never try to cover more that 25% of the surface with any one color, and feel free to mix colors or go back to previous colors.

The end result will be a building with lots of wonderful color texture and it will look like it was painted a long time ago and has faded with the passing of time.

3) Aged and Dilapidated Buildings:

I use the classic technique of washing the wood with thinned black ink before assembly. The wood will warp when you do this. When you assemble the walls and add bracing, weight them down as they dry and the warp will go away. Sometime pieces of brass angle need to be epoxied to the bracing to remove the warp.

This must be done before any of the walls are assembled becaus

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I never prime wood kits, never been a proublem.

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Doing whatever you’re going to do (paint, stain, flat finish etc.) on both sides is good advise in my experience.

I haven’t tried it - I have to admit I haven’t built a wood kit for a long time - but some folks say spraying both sides of the walls with Testor’s Dullcote before painting/staining prevents warping.

14

Thanks for these additional tips, guys, and Kevin, thank you for mentioning the specific product names… that is very helpful. Someone else recommended Delta-Ceramcoat, too.

I didn’t know Dull-Cote was still being made. In fact, I was surprised to find that my local art supply has Testors enamels in the little fun-size bottles – I had thought those were discontinued long ago. I picked up some Testor’s thinner and some red enamel for the Campbell’s grain elevator.

I like to buy in brick and mortar whenever I can, and I was having trouble finding any rattle can primer in the neighborhood short of Rust-O-Leum or auto primer, which I’ve been warned away from as setting up too thick. But I found a gaming shop nearby where they have large tables set up for wargamers and dungeonmasters and every kind of board and card game you can imagine (Mox Boarding House, it’s called) and they have a huge array of brush-on The Army Painter acrylics (TAP Warpaints) in small bottles for painting your dragons and wizards and other gaming figures, but they all have names like Leather Brown and Necrotic Flesh and Toxic Boils, etc. I got some gray primer and some Angel Green for my other kit, the produce distributor kit.

Several have mentioned that they don’t have trouble with warping, or they don’t think the wood will necessarily warp with water-based (acrylic) paints even without primer. I’m going to take the precaution of priming the wood anyway, but I have to say, the wood in this old Durango Press (the original) version of the Perkins Produce is really really really hard wood. The instructions tell you to take “two or three” passes with the blade instead of trying to hork down all the way through it in one pass, but it took me ten or twenty passes with BRAND NEW #11 BLADES to cut the walls out, and I’m laughing while rubbing my forearm after spending all day just getting the parts cut out. “Two or three passes” indeed. I thought that would take half

15

Youse guys make this sound very complikated!

The LION, being cheap (like a boid in Brooklyn) uses corigated cardboard for the constructions of him. And the edge emulates the bracing found on BMT stations. Him uses paint in 2 oz bottles foud in Walmart or Hobby Lobby.

Click on photo x2 for detail (is at the udder end of da kat)

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Lion, that is stunning work. Corrugated cardboard is pretty resistant to curling up, and I must say that in this application the edge of it looks really good and very appropriate. When I build buildings out of cardboard, they look like pieces of cardboard glued together.

-Matt

17

I did not prime this grain elevator as I wanted the peeling paint thing going on which was achieved with the old rubber cement trick.

Some wood kits I have hit with Krylon primer after it was glued together if I want the paint job to look better. I try and hit it before I put the glass in for the windows. When using Krylon primer I hold it way off the model when spraying so by the time it hits it, it is a very fine mist.

The grain elevator was $2.00 Walmart craft paint.

The water tower red is just Krylon primer which was a dead ringer for CP red.

18

This past year I’ve stared in on my stack of Campbell and other “craftsman” wood kits, along with various lasercut kits. The Campbell kits will definitely warp if you only paint one side with acrylic paints, but do ok if you paint the other side with the same paint. Priming both sides also works. The biggest problem with the Campbell kits is the cardboard roofing base - adding bracing (with planning and understanding of the structure) helps a lot to counter roof sag… considering trying styrene replacement in the next kit.

Other wood kits will depend on the manufacturer - some use thicker wood, but many use Northwest siding as their base, which is very thin (and very nice). Bracing is essential, as is painting both sides.

Some laser kits use strong, thick “wood” (seems to have some resin impregnation), others can be almost as thin as the wood kits. Testing on scrap is a good idea, but haven’t had too many issues.

The return in fun and satisfaction on the time spent on these kits is worth every minute, and the solving of the challenges adds to the fun.

19

When I was building wooden kits or scratchbuilding structures using basswood sheet and strip material, the only paints that I had on-hand were from Floquil, and they worked just fine.

When I discovered styrene in sheet and strip material, I got rid of pretty-well all of the wooden structures, and switched first to Polly S paint, then later to Pollyscale paint.
Any stripwood that I still have usually ends-up as flatcar and gondola loads, and I have no interest at all in modelling wooden structures.

Wayne

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Ben, I appreciate your thoughts here. After I finish this Durango Press kit of “The Perkins” (now Booker Perkins Produce by J.L. Innovative) – which seems to use pretty thick wood that did not warp when I primed and painted one side (and which I braced pretty heavily anyway) – I will be starting on the Campbell Scale Models grain elevator. It has some pretty extensive unbroken wall sections and I’ve been worrying about warpage. I plan to prime both sides and brace it with 1/4"x1/4" pieces.

Your notes about the sagging roof are alarming, and thank you for the heads up. I think Wayne said he uses some kind of contact cement for applying Campbell-style roll-shakes to styrene rooves, but I would rather stick with wood and Elmers.

Wayne, your ability to make styrene models look like weathered wood puts you in a league I doubt I’ll ever attain.