Painting Basswood and Dealing with "Fuzz"

[palmerit]

For a side model, I'm working on the Model Shipways Lowell Grand Banks Dory, which uses basswood. Only my second model (my first being the Vanguard Sherbourne), and my first time experiencing the basswood fuzz. 

 

Anticipating this won't take long to finish, I want to make sure I have what I need when I get to the painting stage. 

 

What should I do prior to painting to "de-fuzz" the wood?

 

I've read that I don't want to simply paint over it because that will accentuate the fuzz if anything.

 

I don't know if a basic acrylic primer will do any better than paint (all of my paint, besides what came with the Dory, are Vallejo). (Followed by fine sanding.)

 

I saw mention of first adding shellac, fine sanding, and then painting over. I also saw mention of using sanding sealer (then fine sanding, then painting over). I'm pretty clueless about these things and I'm not entirely sure how shellac and sanding sealer differ. Would either work? Will both be okay for applying acrylic paints over them?

 

I also have Minwax Polycrylic, but isn't that what I would put on AFTER I paint, not before. (Not sure if I should instead have Minwax Wipe On Poly in stead of the Polycrylic - I bought the latter because I assumed it was preferred for using acrylic paints, but then after I got it I found posts saying the Wipe on Poly was better than Polycrylic.)

[Gregory]

I have found that buffing basswood with felt takes care of fuzz.

I use the big felt disks that come with Dremel.

 

Buffing with microfiber might work as well, but I stick with the felt.

Edited October 8 by Gregory

[SiriusVoyager]

I think the simplest solution (though maybe not the most elegant) is this:  If it is already fuzzy, lightly sand with 220 grit sand paper.  If not, then skip that step.  Paint a thin layer.  When dry, lightly sand again with 220 grit sand paper.  Repeat once or twice more until you can paint with no fuzz.

[wefalck]

Water-based paints, such as acrylics, will raise the fibres of particularly soft woods like basswood. For this reason the wood must be 'sealed' before applying them.

 

Wood-sealer is a functional term and various concoctions may go by it. Tradtionally, wood-sealers or sanding-sealers were either nitrocellulose-lacquer or shellac 'filled' with pumice. The pumice settled in the pores and the hard lacquer made for easy sanding. Today, also acrylic-based wood-sealers are sold in order to phase out organic solvent-based materials, but they don't penetrate as well. So look for some solvent-based sealer.

 

The typical procedure is to sand the wood, wet it to raise the fibres and sand again, when dry. Then apply the sealer and when hard sand again. If needed, repeat the last step. Then you are ready for painting. There is absolutely no problem applying acrylic paint over nitrocellulose or shellac sealers, they don't react with each other.

 

Depending on what surface (sheen) you want, there is no need to put any additional varnish or crystalline wax-solution ('Minwax') over the paint. In fact, I would not mix two paint systems. If you want to make the acrylic paint dull matt, use a matt acrylic varnish. Likewise for high gloss.

[palmerit]

I tried sanding with a range of grits (I have all the way up to 1500) and there was still fuzz. I'll see if the buffing method works.

 

So if I wanted to go the sanding sealer route, I'd do something like this:

1. Wet the wood to raise the fibers. Sand again when dry.

2. Apply a Miniwax Clear Sanding Sealer.

3. Sand again and repeat with another coat of sanding sealer if necessary with another sanding. 

4. Paint with acrylics. I usually thin a bit and do more than one coat. Sanding between coats as necessary.

5. (Optional) Apply polycrylic. Sand with high grit and apply again as necessary.

 

Does that all sound right? Or no?

 

I assume that if I wanted to stain the wood (which I don't in this case) I would want to first apply the stain and then apply a sanding sealer, sand, and end with some kind of poly coat. You can't stain after applying sanding sealer. Is that right?

[RossR]

1 hour ago, SiriusVoyager said:

I think the simplest solution (though maybe not the most elegant) is this:  If it is already fuzzy, lightly sand with 220 grit sand paper.  If not, then skip that step.  Paint a thin layer.  When dry, lightly sand again with 220 grit sand paper.  Repeat once or twice more until you can paint with no fuzz.

I use a coat of shellac.  Approximately a 1lb cut.  Then sand with 400 grit sand paper.   I get a nice smooth surface to paint.   I have read that shellac is only good for a few months after mixing.   I use 2lb cut for finishing stained wood, when it is a few months old I dilute with more alcohol to something close to a 1lb cut and use it as “primer” as described above and to set knots so the don’t come undone.   

[barkeater]

Duck carvers who use basswood almost exclusively use gesso as an undercoat to acrylic paint. It gets rid of the fuzzies and gives a nice clean surface to paint over. I don't use basswood except internally, and I don't paint my models except decorative pieces, but I have used it in carving decoys, and it worked.

Richard

[palmerit]

Based on wefalck's comment, I assume a sanding sealer is easier to use than a shellac and does the same thing, right? I'm not keen on mixing my own shellac.

[JacquesCousteau]

In my experience, you don't necessarily need to wet the wood before applying sanding sealer, because the sanding sealer will raise the grain anyway (or at least mine does). But it probably wouldn't hurt. I think the best thing to do would be to experiment on some scrap wood to make sure everything works for you and that there are no weird reactions between different materials. Given the wide range of responses you've received to this question, I think it's safe to say that there's no single way to do it, it's more a matter of finding out what works for you.

[wefalck]

59 minutes ago, palmerit said:

I tried sanding with a range of grits (I have all the way up to 1500) and there was still fuzz. I'll see if the buffing method works.

 

So if I wanted to go the sanding sealer route, I'd do something like this:

1. Wet the wood to raise the fibers. Sand again when dry.

2. Apply a Miniwax Clear Sanding Sealer.

3. Sand again and repeat with another coat of sanding sealer if necessary with another sanding. 

4. Paint with acrylics. I usually thin a bit and do more than one coat. Sanding between coats as necessary.

5. (Optional) Apply polycrylic. Sand with high grit and apply again as necessary.

 

Does that all sound right? Or no?

 

I assume that if I wanted to stain the wood (which I don't in this case) I would want to first apply the stain and then apply a sanding sealer, sand, and end with some kind of poly coat. You can't stain after applying sanding sealer. Is that right?

Ad 4: Sanding acrylic paint is difficult and can only be done really successfully after several weeks of drying. When you apply the acrylic paint, the acrylic molecule begin to form an interlinked network that actually traps some water, this is the reason, why acrylics stay a bit rubbery for a long time, which makes sanding so difficult.

 

When sanding painted surfaces, it is easy to sand right through the paint. Don't use paint as a filler, but rather prepare the surface carefully.

 

And yes, the purpose of the wood-filler is to prevent other things from penetrating. Hence, wood has to be stained first. However, it is not so easy to sand stained three-dimensional surfaces without sanding through the stained part of the wood.

 

As to wetting or not, it really depends on the wood. Some woods barely react to water, while others really swell. It also depends on the direction of how the wood is cut.

 

The use of gesso (Italian for plaster of Paris) is a traditional method of preparing wood sculptures, picture frames and the likes for painting or gilding. It was used, however, mainly in order to add additional features, such als mouldings to picture frames or to save time in preparing complex wood surfaces, such as those on sculptures. Real gesso is quite brittle and breaks off easily. Today, acrylics-based 'gesso' is sold by arts and craft suppliers, which is more robust, being essentially 'filled' acryl gel. For a 'technical' project, such as a boat, where the shape is well defined, I would not use gesso.

 

[palmerit]

2 minutes ago, wefalck said:

Ad 4: Sanding acrylic paint is difficult and can only be done really successfully after several weeks of drying. When you apply the acrylic paint, the acrylic molecule begin to form an interlinked network that actually traps some water, this is the reason, why acrylics stay a bit rubbery for a long time, which makes sanding so difficult.

That explains a lot. I think I had seen some builds - even in the instructions for the Sherbourne I believe - with recommendations to sand between coats of paint. I noticed that it was rubbery, and didn't think that it was because it took a long time to fully cure. 

 

So I guess an advantage of using a non-acrylic sanding sealer on bare wood is that you can sand it more immediately - say the next day. Is that right?

 

I suppose on a hull (or other wood) you're intending to paint, you could do a couple rounds of sealer and filler and sanding until the hull was smooth and then prime and paint (and apply WOP if desired)?

 

If you're intending to stain the wood instead of paint is there a step you can use to prep the surface to get it smooth (since you would not want to use sanding sealer before staining), especially in the case of a softer wood? Or would you just not want to stain a soft wood that could not be finished just by careful sanding of the bare wood?

 

Sorry for all the questions. 

[wefalck]

My nitrocellulose-based sanding-sealer dries in a couple of hours or so, but it also depends on how much of it soaked into the wood. It dries faster on hardwood, than on softwood.

 

Normally, the sanding-sealer is the primer. A primer is used, when painting on certain metals or plastics, where some paints do not adhere to very well. Acrylics adhere well to sanding-sealers. So in your case no primer needed.

 

The only preparation you can do on wood to be stained is to wet and sand it a couple of times before applying the stain. The stain may raise the grain again though. Staining softwood, such as basswood, is difficult, because the grain may keep rising. This then can lead to a mottled appearance after sanding it again. Hardwoods are easier to stain.

 

BTW, I usually do not sand after the second application of sanding-sealer, but rub the surface down with fine (0000) steel-wool. This results in a satin and very smooth surface and reduces the risk of sanding through to the bare wood. Make sure to remove all swarf from the steel-wool or it may rust under your acrylic paint. I use an old clothes brush or a magnet for this.

 

[RossR]

1 hour ago, palmerit said:

I'm not keen on mixing my own shellac.

I understand not want to mix shellac, a few of the benefits from my perspective are you can mix small quantities.  I usually mix 1/4 cup.  Shellac cleans up with alcohol instead on mineral spirits for polyurethane.   My personal preference is alcohol is easier to work with than mineral spirits.   The odor is easier to tolerate.   
 

Sorry if I am getting off topic.  

[wefalck]

Polyurethane is a totally different animal ...

[barkeater]

As a follow up, this is a green wing teal hen made from basswood. I used gesso from an art store and painted over. None of the detail was lost. Notice that you can make out each individual barb on the feathers which had been burned into the wood using a hot knife. I don't know if this would work for you but gesso, at least in my hands, does not obscure detail and gets rid of the fuzzies.

Richard

Edited October 8 by barkeater

[Gregory]

3 hours ago, palmerit said:

I'll see if the buffing method works.

 I have to back off on this.

I have had good results with the felt buffing on other wood.  It has a polishing effect when used with Wipe -On poly..

However, I just tried it on some basswood strip, and it didn't have the effect I hoped for..   Rubbing briskly with some microfiber cloth did seem to have a good effect.

[CPDDET]

I've had good success with Delta Ceramcoat All Purpose Sealer. Any art and craft store should carry it. I get mine at Hobby Lobby.

[Dr PR]

There are many "sanding sealers" or primers. But shellac is probably the best.

 

You can get pre-mixed spray on shellac. Zinsser Bulls Eye Shellac is available at hardware stores, A 12 ounce spray can will last a long time. Use the clear shellac for painted surfaces. For "bright" (unpainted) wood use the amber shellac. Each new layer will darken the wood, so continue until you get the wood color you want.

 

I sometimes spray it on the surface, or just spray it in a small cup and paint it on with a brush. Either method works, but brushing gives you better control of where the shellac goes.

 

Shellac cleans up with rubbing alcohol. But if you want to dilute it use denatured ethanol (alcohol fuel). It dries quickly.

 

You can paint over it with just about anything.

 

****

 

First sand the hull smooth, starting with heavier grit and then fine grit. Keep at it until the hull is smooth enough to paint.

 

Coat the wood with shellac and let it dry an hour or two. Then sand it with fine grit sandpaper. Wipe with a clean cloth to remove sanding grit and dust.

 

Apply a second coat of shellac to seal after the sanding. Then rub it down with #0000 steel wool to get a nice satin finish.

 

Wipe the hull to remove steel fibers. Use a strong magnet to pick off any remaining steel wool fragments.

 

Paint with whatever you want. Use thin coats and apply evenly, stroking from wet paint to dry, and you won't need any further sanding. But if you get runs and need to sand them smooth just apply another coat over the sanded area.

 

If you use acrylic paints allow each coat to dry for 3-5 days, or longer in high humidity areas.

 

 

 

 

[palmerit]

On 10/8/2024 at 12:48 PM, wefalck said:

Tradtionally, wood-sealers or sanding-sealers were either nitrocellulose-lacquer or shellac 'filled' with pumice. The pumice settled in the pores and the hard lacquer made for easy sanding. Today, also acrylic-based wood-sealers are sold in order to phase out organic solvent-based materials, but they don't penetrate as well. So look for some solvent-based sealer.

Ok, so "sanding sealer" and "shellac" basically do the same thing then? And it's just a matter of preference which to use? Googling around, I saw some people call sanding sealer "snake oil" and others say that shellac was not appropriate for model ships. 

 

So if painting, it'd be:

(1) sanding sealer or shellac

(2) sanding

(3) sanding sealer or shellac

(4) 0000 steel wool, using a magnet to remove to fragments

(5) paint

(6) (optional) some kind of wipe on poly (polyurethane or polycrilic)

Is that right?

 

What if I'm staining wood?

 

I understand that the first step would be to sand, and possibly wet and sand. And sand some more. Then I'd stain.

 

Not clear what comes next.

 

Would I do a light stain and then sand again? Or do another light stain and use 0000 wool?

 

Would I do sanding sealer or shellac after that? Would I just do something like 0000 wool after that?

 

Would I then do some kind of wipe on poly?

 

Can you tell I've never really done any woodworking, at least nothing fancy.

[wefalck]

Not sure why someone would say that shellac is not suitable for ship models. It has been used for centuries on all sorts of fine woodwork, including ship models.

 

In carpentry, shellac was used to build up what is called 'French polish': the wood was rubbed down with a pumice stone, dedusted and then thin shellac applied with a brush. It was then rubbed down with the pumice stone again, dedusted and somewhat thicker shellac applied. This procedure was repeated several times, but the shellac was applied with a tampon, a lint-free rag-bag filled with wool, stroke by stroke and very quickly. It results in a very glossy, glass-like finish, when done properly.

 

The effect of the pumice is double, it has a sanding effect and the abraded pumice fills the pores of the wood, which then is solidified with the shellac.

 

To make things simpler and quicker, today sanding-sealer are sold, which are basically a suspension of pumice or other fine-grained filler in a lacquer, which could be shellac or the cheaper nitrocellulose lacquer.

 

To your last question: after staining you probably need to rub down the wood lightly, but don't use steel-wool at this point, as the swarf would get locked into the wood pores. Light sanding. Then comes the same procedure as if you were preparing for painting, but of course the last application of varnish (e.g. shellac) is not rubbed down anymore.

 

As shellac dries very fast, it cannot really applied with a brush as last coat, which is why a tampon is used.

[wmherbert]

I use this over bare wood, such as planking.  Let dry over night, then 2nd coat.  Again dry over night before sanding.  Then putty  sand and then color coats. 

Sanding  with 220 or 320 between coats.

[RossR]

3 hours ago, palmerit said:

others say that shellac was not appropriate for model ships. 

Are you confusing shellac and lacquer?   Lacquer creates a thick coat that can look out of scale on a model.  

[palmerit]

3 hours ago, RossR said:

Are you confusing shellac and lacquer?   Lacquer creates a thick coat that can look out of scale on a model.  

That could well be. I went down a bunch of rabbit holes trying to figure things out before posting.

[Dr PR]

Some people say shellac is the only thing to use ...

 

It is sorta like a ship's rigging - there are as many versions as there are people.

[wefalck]

Lacquer is (at least in my understanding) a generic term, see https://en.wikipedia.org/wiki/Lacquer. Different materials and appropriate solvents can be used to prepare lacquers for application, such nitrocellulose in different types organic solvents or shellac in alcohol.

 

Thus, shellac can be used to make sanding filler when 'filled' with some suitable powder or as lacquer, when applied neat.

 

Depending what type of resinous substance (see above Wikipedia article) is used, the lacquer can be more brittle (e.g. shellac) or more elastic (e.g. acrylics, mastic). More brittle lacquer is more amenable to sanding obviously. Conversely, it can make rigging break, when used to soak thread in it (note: a drop of shellac on a knot or splicing doesn't do much harm).

[paul ron]

the sealer actually hardens the soft wood thus allowing you to sand off the fuzz n not raise the grain again. ive used clear acrylic, laquer, varnish, poly. all work well. my final coat of paint sits nice n flat. if your final coat of paint is thined, then light sand n recoat.