Question about paint

[11320 Titanic]

Thanks Bob. This 3 model beginner's set from Model Expo is my first experience working in the wood medium. I have done one card, HMS Alert that came out better than expected. Card is not as messy as wood, nor requires much tooling.
I am spending more time fixing gaffs than building. The balsa is flimsy and breaks easily.
Thank you for taking the time to respond, it is greatly appreciated.

 

[11320 Titanic]

For wooden ship models, not a fan of water-based paints either. Never found a brand I was happy with, especially airbrushing. I have some old Floquil but primarily use Testors and Humbrol enamel paints. It's easy enough to mix the colors you need.

I used Testors, I used to store the bottles upside down, they seemed to go longer before drying out. I brushed them on and also sprayed them. BCk then my modeling was usually plastic kits with a few balsa rubber band powered airplanes

 

[Bob Cleek]

For wooden ship models, not a fan of water-based paints either. Never found a brand I was happy with, especially airbrushing.

I can see a value to water-based acrylic paint for use on silkspan for making scale sales. It's water base is an advantage in forming the wet silkspan into sail shapes in that instance. Beyond that, while I try to keep an open mind, I can't see any value to using water-based coatings anywhere near a wooden ship model. There are just too many "cons" to overcome the "pros" with the stuff. I'm afraid when it comes to water-based coatings, as much development as has been done over the years, their production remains an attempt to spin gold from straw.

 

[Bob Cleek]

The balsa is flimsy and breaks easily.

Oh, definitely lose the balsa wood. It's an unfortunate hobby shop legacy from the days of rubber band powered model airplanes where its light weight outweighed its shortcomings. Replace it with after-market basswood, a decent selection of which can usually be found in crafting, hardware, and home improvement warehouse stores. Midwest Products is a popular brand and they have sales racks in a lot of stores. It's relatively inexpensive. Seal it with thinned shellac. When the shellac is dry, it sands well without "fuzzing." Without the shellac sealer, it's hard to sand to model-standard smoothness. See: https://midwest-products.myshopify.com/collections/basswood

 

[11320 Titanic]

I used Midwest on my n scale train layout. I made my own buildings, saving a lot of $$$. A few dollars replaced buying plastic kits that would run $30 t0 $60.
Now, when you build your ships, do you shellac before starting? If you are going to stain, stain first then shellac? Does shellac take paints well?
I am finding after using a few types of glue that a PVA seems to be best for ship models. Alenes is good for card models but not so good for wood models. I tried Testors Metal Glue for the metal fittings but it doesn't work at all. I tried contact cement but you have no wriggle room.
I also found that acrylic paints can distort balsa wood, does it distort bass wood too?
Does bass wood respond to heat for bending as well as balsa?

 

[11320 Titanic]

I used Midwest on my n scale train layout. I made my own buildings, saving a lot of $$$. A few dollars replaced buying plastic kits that would run $30 t0 $60.
Now, when you build your ships, do you shellac before starting? If you are going to stain, stain first then shellac? Does shellac take paints well?
I am finding after using a few types of glue that a PVA seems to be best for ship models. Alenes is good for card models but not so good for wood models. I tried Testors Metal Glue for the metal fittings but it doesn't work at all. I tried contact cement but you have no wriggle room.
I also found that acrylic paints can distort balsa wood, does it distort bass wood too?
Does bass wood respond to heat for bending as well as balsa?

I have a lot of dried up Testors paint. Does anyone know what kind of oils they used in their paints? I bet a lot of us could bring our old dried out testers back to life with that knowledge.

 

[Bob Cleek]

Now, when you build your ships, do you shellac before starting? If you are going to stain, stain first then shellac? Does shellac take paints well?

I use clear shellac on everything. It is a great sealer and fine sanding surface stabilizer which enables sanding smooth without raising "fuzz" as is likely with the softer wood species. One of shellac's more valuable properties is its ability to penetrate and seal wood without raising the grain as water-based coatings do. This makes shellac essential for getting a good scale finish job out of water-based acrylics.

On rare occasions when I might stain a piece, I would stain it before applying the shellac so the stain would soak into the wood. That said, I can't think of any situation where I've done that in a very long time. The fact is that if I am going to finish a piece "bright," (varnished or clear coated to show the wood color and grain) I'm going to use a finish wood for the appropriate look I want, not try to stain a piece of inferior wood to look like the finish wood. There's so little wood in a model that there's really no excuse to not pay the cost for a finish wood species that can speak for itself without being stained to create a faux finish. Moreover, considering scale appearances, I don't use much bright finish wood at all because at scale viewing distances wood figuring will be invisible for all intents and purposes, so what's the point?

Shellac takes paint wonderfully. It's about the only universal sealer that everything sticks to well. Shellac is also an excellent cement for rigging knots and for forming coils, hanks, and catenaries in line. Just a small drop applied to the knot will soak right in and dry very quickly, eliminating those frustrating "self-untying knots" that occur as soon as you cut a line to length after the knot is tied! Shellac also cleans right up with alcohol and can be easily removed, or knots untied, by applying alcohol to dried shellac. Thickened shellac is also a relatively decent adhesive, although weak in shear, as are most cements that dry to a hard consistency.

 

[11320 Titanic]

Wow, thank you.

 

[DAWarden-(Jaager)]

do you shellac before starting? If you are going to stain, stain first then shellac? Does shellac take paints well?

Do you shellac first? = No. Not if you intend to bond anything to it. PVA bonds to the surface. The more surface area - the better the bond.
By using shellac first two things happen: the wood has less surface area - the shellac is between the wood and the PVA. The PVA is bonded to the shellac and the shellac is bonded to the wood.

Stain before shellac? = That depends on what is meant by "stain".

A dye stain (or just dye) is pigment molecules DISSOLVED in the solvent. As far as the solvent is able to penetrate into the wood, the pigment molecules go with it. Molecules are far too small to be seen using a light microscope. Shellac would block solvent penetration and thus pigment molecule penetration. So - No.

A pigment stain is pigment granules suspended in a binder (and a liquid carrier). Granules are visible using a light microscope. They will look like boulders banging into each other. Shellac first - especially if the first coat is a half saturated concentration (diluted 1:1 with alcohol) - as a primer - is probably the best primer for most any other follow-on finish. It provides a smooth even surface for the binder. For enamels a second coat of full strength shellac may be of more quality producing. So -Yes.

Paint is also pigment granules suspended in a binder. A pigment stain just has a lower concentration of pigment granules. Some pigment stains also contain dye molecules. This is for the advertising copy. In practice the dye component adds nothing.

Does shellac take paints well? = There is no better primer or base. It takes a deep search to find a finish that is not compatible with shellac.
Now, if I contracted a prion disease and my ability to reason had severely degenerated enough for me to consider using an acrylic paint, I would probably only use a one coat primer of half saturated shellac before apply a coat of water based acrylic paint. Shellac "likes" water. Grabs as much as it can hold and turns white.
Those who freak out about hobby use of organic solvents enough to pass legislation or ordinances against its availability would probably have been inhabitants of the back wards at Eastern State in the 1950's (pre Thorazine). Benzene - don't want any exposure, MEK - probably not. lacquer thinner - outside - the real stuff is fierce. Mineral spirits, naphtha, acetone - require respect - do not breathe - but gasoline is not any safer.

I have a lot of dried up Testors paint. Does anyone know what kind of oils they used in their paints? I bet a lot of us could bring our old dried out testers back to life with that knowledge.

Paint is a pigment, a binder, a solvent (a carrier/suspending liquid - not sure much is dissolved in this gemisch). When the solvent evaporates, the binder polymerizes (undergoes a chemical reaction) (becomes a much much larger molecule that will not dissolve in much of anything and would be useless even if you could dissolve it).

Enamel paint - oil based paint - the solvent is organic - mineral spirits, terp, naphtha, lacquer thinner, etc. - the binder is linseed oil or a similar plant based polymerizing oil with a catalyst to speed the polymerization reaction (dry), When dry it is either a coat on something or a forever coat at the bottom of a jar.

Now, if you had started with a dry powder pigment and suspended it in shellac and that had dried in its jar, an alcohol - ethanol, methanol, isopropanol would make it usable again. But even in this situation I would start over with fresh pigment and fresh shellac.

If you start with tubed artists oils and suspend that in shellac to make your own shellac paint (can't find a reason to do this) it will not redissolve if it dries in its jar. Tubed oil paint includes a binder - usually linseed oil with a bit of cobalt catalyst - but not much solvent. If you add your own organic solvent to whatever brushing or spraying consistency you desire, you have made your own Testors for much less money. If the tube is kept tightly sealed and you only mix up only as much as needed for a particular job and toss or better paint it on a piece of scrap - your version of home made Testors (the tube of paint) will probably have a longer shelf life than you will. Instead of storing mixed paint, you store a 3x5 card with the exact formula.

 

[11320 Titanic]

Interesting and thank you.

 

[Bob Cleek]

Do you shellac first? = No. Not if you intend to bond anything to it. PVA bonds to the surface. The more surface area - the better the bond.
By using shellac first two things happen: the wood has less surface area - the shellac is between the wood and the PVA. The PVA is bonded to the shellac and the shellac is bonded to the wood.

In theory, yes, I get it. In practice, I've never experienced any adhesion problems resulting from shellac used properly as a sealer. Perhaps I should have provided more detail when recommending the use of shellac: When shellac is used as a sealer, it is applied thinned so it doesn't build up on the wood's surface.

I use Zinsser's Zinsser's Bulls Eye canned clear ("white") shellac which is a "three-pound cut", meaning it is a shellac-based sealer that is designed for use on various surfaces, including wood, metal, and masonry. It is recommended to thin the shellac with denatured alcohol for application, and it is not recommended to thin it much further than this cut. When a can is fresh, I use it straight out of the can, but over time, when exposed to the air, the alcohol solvent will evaporate so I occasionally add denatured alcohol to thin as required. (I buy denatured alcohol at the paint or hardware store in the gallon tins and decant it to smaller dispensers if I want. It's a "shop shelf staple" in my shop (along with acetone, which I purchase the same way.) Buying in bulk provides a substantial savings over time when the material is cheap because the packaging isn't.

Zinsser's Bullseye premixed canned shellac is prepared and marketed as a sealer. In that formulation, it's fine for sealing wood on models and for cementing rigging knots. Shellac can also be used as a clear finish coating and, when done correctly, is one of the best. "French polished" hand-rubbed built-up shellac finishes are the hallmark of fine antique furniture. Shellac is also a valuable archival adhesive and can be used to laminate card stock for modeling purposes. These latter applications, however, require heavier cuts of shellac, which is to say a much thicker solution of lac flakes and alcohol which would produce a coating much too thick for sealing modeling wood. Shellac can also be purchased in "flake" form for dissolving in alcohol as needed. If one does that, they should not mix too heavy a cut if they are using if as a sealer.

When I apply thinned shellac to bare wood, the wood instantly absorbs the alcohol along with the shellac dissolved in it. When the alcohol evaporates, there is left only a very thin coating of shellac on the surface of the wood, and the wood surface retains almost all of any surface roughness it may have had before the shellac was applied. When sealing wood, the sealer coating should never build up on the surface of the wood. Building up a coating on the wood for sanding to fine smoothness, as all visible model parts should be before applying finish coats, is the job of a sanding basecoat. (They sell "sanding basecoats" that purport to do two jobs at once. They are for house painting, not models. Don't go there.) The sanding basecoat is loaded with chalk ("whiting") which makes it more opaque to provide a uniform color base for the finish coat(s) which are not made to "cover" color unevenness in the substrate and to make the basecoat easy to sand when it dries. (I will usually sand my basecoats on hulls to 600 grit to get a perfectly fair surface for my finish coats.

The secret to getting a good finish on models is to try to at least make your finish coatings appear to be in the same scale as the model. Of course, it's not possible to really finish a model with a coating schedule that is of actual scale thickness, but the point of the exercise is to keep it as thin as possible so that the coatings you apply do not obscure, if not obliterate the crisp detail of the scale model. I would say that of the many pitfalls of the rather complex craft of finishing in all its aspects, the one mistake most often made by novices is applying their coatings too thickly. Multiple very thin coats are always better than a few thick ones. (And care must be taken not to sand off the coat you just applied when "sanding between coats.")

I've never had any problem with subsequent finish coatings laid on top of shellac. I will say that I don't recall ever having any problem with applying water-based coatings (acrylics) over shellac sealer, either, but the truth of the matter is that it's been a long time since I last used water-based coatings on a model and can't imagine ever doing so in the future. Neither have I had any problems using PVA adhesive to join shellac-sealed wood. That said, I try wherever possible to mechanically fasten parts together or, as in wooden structural assembly, to "engineer" sufficient strength into the structure such that the whole is not solely dependent upon the adhesives to hold together. Where that is not possible, I will use epoxy, cellulose nitrate ("Duco,") polystyrene, or hide glue adhesives as more appropriate than PVA.

​

 

[DAWarden-(Jaager)]

When a can is fresh, I use it straight out of the can, but over time, when exposed to the air, the alcohol solvent will evaporate so I occasionally add denatured alcohol to thin as required.

I early on caught the shellac flakes bug. As I understand it, the more refined / closer to water clear is the grade: the less wax. The wax acts as a solubilizer in alcohol.. The less wax the lower the concentration of shellac at saturation. For super blonde I think that is 2 lb cut. For amber or the less refined grade just above it it is about 4 lb cut. I did a wet finger - back of the envelop calculation and 4 lb cut is a tad more than a 40% solution.
1 lb =~ 375 g 1 gal=~ 3800ml 375/3800 = ~ 0.1 or 10% With my el cheapo coin battery electronic scale I weigh 20g of super blonde and dissolve it in 100 ml of alcohol - smaller volume - less storage time worry.

Now for some more run=on thinking - it is sort of a paint or at least a finish:

For my present long term project - the NMM original model had a dark finish. My thinking - OK - I will just give my Hard Maple a few coats of garnet shellac. Reading the model description on NMM - turns out the model was Japanned. It was an Admiralty order to the model builder who apparently was not keen on doing it. After waiting for about four years, the Admirality had to hire it done by someone else. Turns out Japanning is not shellac at all. It is bitumen / asphaltum - little different from crude petroleum. Likely from seepage since it was 100 years before Edwin Drake. The stuff has been liquid for hundreds of million years so it ain't gonna dry on a model. It is a liquid. It is not something in a liquid. Turns out it is mixed with boiled linseed oil and frozen in the polymer matrix. Nope! Not interested. Garnet shellac will have be good enough.

 

[11320 Titanic]

Interesting and thank you.

I primed the hull with acrylic primer. Now the finish coat bleeds into the primer. I am going to finish this one then reorder the same and try redoing it with the knowledge gained from the goofs on this one. And without acrylic paints! I now know where the week spots are on the stem, and will reinforce them before adding the bulk head framing. Though I may just go to my local hobby shop and pick up some Testor's oil based paints.
Some of the glues I tried that were not so good.
The Evergreen yellow wood glue works very well.
Newbie is learning.


I found an older spray gun and compressor in the cellar while cleaning out my work bench. They work!!!!
From now on I will spray my primer and top coat. I'll see how that acrylic paint does when sprayed on, I already know how oil based sprays on as I used that during my plastic model days.