Shellac removal

[nhguy]

It's been a bit since I have been on here. Some may remember my upcoming kitchen renovation. Well the time is here. I've been pulling the trim around the doors to stain to hopefully match the kitchen cabinets. I started stripping off the shellac and thought with six doors I will be here forever. I found a technique of laying a plastic sheet slightly longer than the trim piece, then wrapping it in a length of paper towel. I soak it with denatured alcohol in a spray bottle, then wrap the plastic sheeting around the piece fairly tight and allow it to soften for 20 minutes. Upon unwrapping lightly spray with the alcohol and rub with coarse steel wool. The edges I found scraping with the edge of a chisel took off most of the finish. Then you again can spray with alcohol and rub with the steel wool. Anyway, I hope that helps some of you. Perhaps this is not a new technique to some of you savy house restorers, but it worked nicely for this job. I will post some photos once the kitchen is done.

[KenN]

The plastic keeps the alcohol from evaporating? Good idea I will have to try it next time.

[nhguy]

The plastic keeps the alcohol from evaporating? Good idea I will have to try it next time.

Yes, it does and I must say it works very well. I sanded and stained the trim pieces today. Tomorrow the first coat of satin lacquer.

[Gothichome]

Nh, what a great idea. Glad it worked out well. Could your technique be adapted for trim still in place? Maybe mask the wall, wet the trim and then tape your plastic to the wall?

[phil]

alcohol is what shellac is made with, you can dissolve the shellac flakes in alcohol. If you put more overtop then the layers meld together. this is different from say oil based paint where a new layer does not mix with the lower layers.
so if you go at it with a cloth soaked in alcohol you can dissolve it. youc an also choose to clean the top layers to remove dirt then put more and leave whats there as a base.

My way would probably be to reach for lacquer thinners. its a stronger solvent with stronger odors and probably a higher fire risk so use may require better ventilation and more PPG you can refer to the MSDS ( material safety data sheets) for that rather than me making them up. the MSDS sheets can come from the supplier or you can just look them up this is free information that legally needs to be provided .
It might depend where you are doing it. and how well it is ventilated but you may find it a lot faster. you could experiment a little to check. I normally keep both on hand.

Acetone is even stronger but I dont think you need to go to that level. I'll use that for things like quickly wiping down acrylic enamel paint to get it really clean and a better bite between layers or for removing tape residue etc. Acetone is used for cleaning fiberglass tools and such. all these have fire risk potential and I'd wear a chemical respirator with an appropriate cartridge if you spend much time near it. Alcohol is a bit less harmful but it still burns really well.

stripper may work but Its kind of a waste of product and leaves some residue usually there are different types and brands.


shellac has a low melting temp so if you are stripping it with a heat gun and knife with paint over top it is fairly cooperative. even if you paint stuff you can use shellac as a sealer and it also makes things easier if you ever do want to strip the paint that way.

Phil

[KenN]

I have been doing a variation of a “spray, scrub, spray, wipe” technique I saw in videos here:

https://coopersstripclub.com/tutorials/

On the flat sections I will use card scrapers to get the rough stuff off first. Then I was spraying alcohol, wait a bit, scrub with steel wool, spray and scrub again until the shellac is like a slurry, then with a clean rag wipe it up. A little section at a time.

The rag will pick most of it up. It does take some time for the initial application of the alcohol to soften this old shellac up, and it does evaporate fast, so I will try the plastic sheet idea on the next one.

[phil]

there is a bit of a knack to getting behind a card scraper and in maintaining the blade and how to burnish a hook on the blade if necessary. I got a set that includes a little holder with an adjuster that holds the blade in a slightly bent position. If you have strong hands you dont need the holder but in some cases such as scraping towards yourself it helps. if your hands aren't that tough they help with fatigue. I like to use mine when I want to pull towards myself as its hard to hold it that way but I do more by pushing it with my weight behind it, thumbs toward the center fingers holding the edges and I control how much bend I want by the way I apply pressure to the blade.

there is a big difference to the ergonomics if you can get overtop pushing down on the work on a firm workbench as opposed to trying to stand on a ladder and work in some awkward position to some attached piece.

if you can put things on a table , clamp them down so you can get your weight down on the piece then you dont need any solvents or strippers, you can just shave the surface off. in this way you dont need to play with chemicals.

the "kit " I got comes with some different thicknesses. I've also made one with a roundover that I use for corners of baseboard moldings etc.

in a pinch you can use a piece of an old handsaw if you have a rusty one or one with a crack you can use a zip disk or a cutoff disk in a dremil to cut the stuff. it needs to be hard and springy enough to hold an edge but yet be able to bend and be filed.
my kit came with a tool to burnish the blade. or if you just sharpen it square like an ice skate you can just put it in a vice and take a big screwdriver with a hard shank and sort of press down and rub the edge to form a little hook , with the hook you can hog off bigger shavings so it works faster. for fine finishing you don't need a hook on the blade.

the "kit" also came with a jig that basically holds a mill file square to the blade. You can just sharpen them by putting it in the vice and draw filing it with a mill file, but the holder helps if you want to touch it up out where you aren't near a vice.

another way is by sander, that could be a belt sander or a ROS or a table sander or woodwork shops often have a drum sander. Its less work to sand but it isn't always possible depending on the piece. You can dig dips with a belt sander but if you are careful I find they work for a lot of things because they remove a lot fast, once I break the surface then I use the card scraper for finishing. If it isn't flat or if you prefer to not make all that dust, you can use a hand plane before the scraper.

in some cases where patina is to be preserved you can do it chemically, that way there isn't much wood removal. I prefer to just finish the wood. I use dainish oil ant turpentine to get two or three coats down , then if I want it darker I mix just a tad of stain into the oil and do more coats. after that I can put more coats of oil and leave it oil or or shellac or lacquer or polyurethane. It depends on the level of protection the surface needs and on what's original. If its an antique I usually try to stick with what it had. The look of only oil gives a really nice finish. If I need it hard wearing like floors or kitchen counter parts or bathroom parts then I use poly for the protection of water. If it's 30's and newer production furniture it is often lacquer. you can get spray cans or if you are more serious a compressor and spry gun works best. some antiques and probably your old floors were shellac. you can do shellac after the oil and finish with poly or lacquer if you like.

I prefer rubbed finishes sometimes. You can apply the shellac or poly by wiping. sometimes like with boards that are on saw horses I just take a stick and tape a bit of towel around it then a piece of bed linen to hold back the fibers and then you can pretty much just dump a little pool on the board and run the length with the stick that smooths the surface and there are no brush strokes. If you like you can brush it on instead, and sand between.
if you want a really high shine you can use french polishing techniques. There are food videos on that on you-tube. If you go to that level you may also look at using grain fillers.

yet another way is to use a sharp carbide blade in a holder with a handle and pull it . you can get the carbide scrapers. I have to change blades in planers and things so sometimes I use the spent blades which are still pretty sharp to avoid always buying them. If you have a sharp carbide scraper you can pull the finish off like that. I sometimes ease the corners a bit to prevent gouging. you can pull the paint or shellac right off with a carbide scraper but if you aren't careful you can disturb the surface too much by gouging it. I'd do that on a window or a window sill but not an antique table for example. It makes less dust than a sander.

If you use the danish oil or linseed oil and turps, put lots on the first coat, wait 15 mins and dry down , dont add any color to the first two coats or it will amplify and surface defects. On subsequent coats just let it soak what it can and rub all you can off. repeat that as often as you like , that's a nice finish in itself because then there is no thickness of the finish on top of the wood so you see down into the ribbon and reflection of the grain. I often do this to pop the grain and reveal the ribbon , then If I want I use other finishes over top to sort of lock in the appearance.
if it gets sticky use more turpentine and rub it down better with dry cloths after each session.

sometimes when you work over a surface and then apply the oil it shows sanding defects , bruises etc. I like to apply the oil first and look at it then work on any areas where the defects pop upon application of the oil. If you go straight to a type of varnish then it can pop the defects but also seal them in so I prefer to have a look at it like that with just oil first. this also allows me to check and correct any work I did with putty. because any filler changes color as well as the wood on the first application so sometimes I find my filler shows , if so I correct it and continue. If you wor over one area more and put more oil it is invisible and you aren't backing up snf removing the finish to fix the issues. with the putty I use Blendall powders and mix them with the filler to get the color just the way I want to prevent it being noticeable.

as an example I sanded my floors and used the edger , then after applying oill I see marks from the tracks left from the little steel wheels on the edger. it dents the surface and makes circular marks. so I work them out and make sure I am happy with the appearance before continuing, in this case with poly.

if there is blush in the surface of shellac or lacquer it is often a whitish appearance in old finishes. you my also see crazing cracking or a pebbled finish. you can use amalgamator. this helps soften the finish and allow the blush to dissapear. in this way you can restore a finish without removing it. for example I'm working on an old chair with carvings so I choose not to strip it. I didn't want it all whitish but I also didn't want to sand into the original patina. In this case I try to restore the finish rather than removing it which would be damaging. My aim is for it to still look old and not a showroom new finish. I dont want to sand or scrape because that would remove the patina and detract from the piece.
some techniques are applicable to antique restoration but with a whole house you have to consider time. the amount of surface and the time spent needs to be reasonable.
I like to just get it looking nice and finish it with just oil, then later I can use other coatings if desired. this way I can move ahead faster and you dont need a dust free room to wipe on oil.

one if the nicest finishes is simply just oil , you can try getting a couple of coats down and then use about 320 wet or dry sandpaper. get a dish, put a little oil and turpentine in the dish, wear gloves, then dip the paper and sand. keep doing that and it will drive all the dust you create into the pores and result in a really nice shine with no layer on top of the wood. it leaves a silky smooth surface and you can replenish it now and then , I like this way for things like handrails. that way they dont have that sort of squeaky feel you may get with other finishes. its more like an old handrail worn smooth from millions of hands running over it. that's a good way to maintain axe handles and things too.

I like to pull my trim , remove paint strip it sand it, fill any old nail holes with appropriate colored putty then finish it in oil then put it back. I may use the old locations for nails or new ones. if you are using casing nails then predrill the holes just a bit smaller than the nails to prevent cracks. sometimes I hand drive the very thin nails used for nail guns. I just make a piece of steel rod about 1/4" with a hole that slips over half the nail so they dont bend over before I get them most of the way down. because they are so thin.

if you break through the top surface of the wood you can expect natural darkening to occur from sunlight. over the next six months you will see a change and it will continue to darken. some finishes like some of the water based finishes may have UV blockers. they can prevent darkening. Usually I want the darkening to occur. You might want that if you were say doing something with light wood and wanted to to remain light.