I hate sanding between finish coats

[Jim Barstow]

I typically sand with 400 grit between finish coats but it is a long, boring process that I hate. (My favorite finish these days is minwax wipe-on poly diluted with a little mineral spirits and with a dash of tung oil added.) Does anyone have a magic finish recipe that provides a satin (NOT glossy) finish that doesn't require the hours of sanding? Should I try using an HVLP spray? I've been doing this for 30 years but surely there is some new finishing technology that provides a perfectly smooth finish sanding free.

Sanding the Greene and Greene crib I'm making takes hours between coats

[Mike Henderson]

My experience is that it's necessary to sand after the sanding sealer to get a smooth coat of the final finish. Alternately, wait until you put your first final coat on, then sand and shoot one more coat.

I use water borne finishes so the water raises the grain, which means I have to sand somewhere in the schedule.

Mike

[I spray my finishes.]

[Leo Graywacz]

You'll have to sand the first coat, otherwise what it feels like after that will be what you get in the end.

With polyurethane you are forced to sand, it is this sanding that the next coat will bond to.

If you are spraying lacquers, pre cat or post cat lacquers you can eliminate the rest of the sanding as long as you are spraying within the window. With lacquer you can respray anytime, it melts into itself. With a precat lacquer you can spray another coat hours later without sanding. With a post cat lacquer you have to be pretty quick, and it depends on the product also. If you respray between 1 and 2 hours of drying you won't need to sand.

All the manufacturers insist you scuff between all coats.

[Mark Bolton]

It sounds like you should investigate some different finishes. Hours of scuff sanding or de-nibbing is tough to quantify because you could be talking about a commercial bar, entire kitchen, or a jewelry box.

If your brushing your finish a lot of sanding is inevitable as each coat is far from flat to begin with. You could switch to a self sealing waterbourbe laquer and be out in two coats with a 320 scuff in between. It all depends on how you work, what your desired outcome is, and your shop and equipment.

if your happy with wipe on poly of all things there are dozens of easier options out there.

[Jim Neeley]

A well-tuned hand scraper works well for quuickly de-nibbing while leaving a beautifyl dust-free finish between coats. You do have to learn to take a fine cut however.

[Andrew Hughes]

Some of my best work have almost as much time finishing as building.I really don't care for trying to finish everything at the end and try to build the finish as I go along.
I good to keep the same energy thru the whole piece really pays off in the end.

[Jamie Cowan]

I really like General Finishes gel urethane, which I foam brush on, and then wipe off with a rag. Pretty close to perfect, if you hate sanding.

[Mark W Pugh]

You guys are way beyond my experience level, but I really like this article. May not apply to what you are using, but does debunk the waterborne issue, in my mind anyway.

http://www.hardwoodlumberandmore.com/Articles/ArticleViewPage/tabid/75/ArticleId/28/Pre-Raising-The-Grain.aspx

[Daniel Rode]

I guess I don't like sanding either but It's often a necessary step in the process of completing a piece. This is my hobby; low volume, slow pace. I might taker a different view if I were doing this for a living and sanding between coats often.

For me, the need for sanding (or lack thereof) is a result of other choices. I choose a finish based on the look I want and the protection the piece will require. Then, I take into account my familiarity with or preference for working with certain finishes. For example, oil-based satin wipe on poly is my favorite all-around finish. For many projects, it provides a look I like, excellent general protection and it's easy to apply thin even coats. It also means I will need to sand between coats.

For my next project I'm going do something different. I'll start with a de-waxed shellac sealcoat and then apply a water based poly. Probably the same amount of sanding but it smells better and cleans up with alcohol and water.

[David C. Roseman]

Jim, if you can get your hands on a small can of General Finishes' Arm-R-Seal Satin, I think it may be close to what you're looking for. Be sure it's the Satin finish, as it comes in Gloss and Semi-Gloss.

I "discovered" it a couple of years ago when a clerk at a local Woodcraft suggested it and gave me a small sample bottle (doubt those are still available). Wipes on, and thin coats can be recoated within an hour or two without sanding, depending on the conditions. On smaller, turned projects, I can actually recoat within 15 mins. altho GF doesn't suggest that. Sanding with 400 grit between coats is not necessary for adhesion (as opposed to removing nibs and settled dust, which I gather by your question is not your primary concern here). That makes is pretty close to a "magic finish" for me. :)

Your present mixture of thinned Minwax WOP sounds pretty good though, so not sure how much difference you'll see.

David

[Jeff Duncan]

Spraying can provide a finish that's ready to go once you've invested in the equipment and have gotten past the learning curve. Of course you still need to sand between coats;)

I haven't tried scuffing any type of brush on finish in....well, a long long time, so can't help you there. I can say with the pre and post cat finishes I spray scuffing is very quick. You basically just want to knock off the nibs and have a scratch pattern for the next coat to cling to. Essentially your just wiping all the parts once or twice with paper and/or sponge and back into the booth. I haven't done a crib so couldn't even ballpark, but hours sounds like maybe a bit too much scuffing? For say a typical 5 piece cabinet door it would take maybe a minute or two per door for scuffing. Again, not trying to get it perfect, just scuff off the nibs and move on, the next coat is going to cover up everything you've done anyway! The one exception would be for surfaces that need to be dead flat....like a table top. In that case it's beneficial to spend a little time getting and keeping the top flat for that last coat.

good luck,
JeffD

[Prashun Patel]

Jim,

I don't believe you need to sand between coats as much as you think you do. In fact, if you sand between every wipeon coat, you're doing yourself a disservice.

By adding tung oil, you are actually creating an oil/varnish, which really should be wiped OFF after it's wiped on. Done this way, after many coats, you will end up with a sealed and satin surface. No build. No gloss.

By eliminating the tung (and in fact, if you are STARTING with a wipe on poly, elminate the additional MS) you will have a strict wipe-on poly, that can be wiped on and left to dry. The trick to eliminating sanding is to make your coats thin. For the first coat, the other posters are correct: soak it in and keep soaking it in for like 10 minutes. Wipe off any pooling after that time. Next day, you have to sand it smooth. For the next N coats, don't "paint" or "lay" it on with a rag. Just get the surface slick with a finish-moistened rag. Don't work it too much. Look at it in raking light to make sure you hit all the spots. Touch up a little as needed, and then leave it alone. Every 3 coats, you can 'sand' - but only to remove dust nibs. Take your 400g sandpaper just wipe it quickly over the surface. No heavy sanding required. I've gotten blasted for saying this here before, but it shouldn't take you more than a couple minutes to 'sand' a 4x8 surface this way. Wipe off any dust. If you are wetsanding here, then let any residual water or ms evaporate for a while before putting more coats.

Semigloss poly works extremely well in both of the above applications. I've tried Minwax and General Finishes Arm-R-Seal. Both work fine.

Once you learn to apply it well, (dare I say, 'properly'?), you may reach the same conclusion as I: on a thin build surface, there is little difference between different starting materials regardless of varnish species, brand, or sheen.

[Art Mann]

I used to use Minwax Wipe On Polyurethane almost exclusively and I never had to sand to the extent you apparently are. Just a light quick once-over with 320 or 400 grit is all it took to eliminate the dust nibs. Any more sanding and you are just removing good finish and increasing the requirement for subsequent coats. I don't understand the reasoning behind diluting with mineral spirits and contaminating the mix with tongue oil. Maybe you know something I don't but if I want a tough polyurethane finish, then I don't want to compromise the results with any kind of oil.

[Robert Chapman]

I use the same finish mixture and usually use 320 grit for the middle 2 out of 4 or 5 coats - then 400 and 600. I use Minwax Satin Poly for one third of the 3 part mixture. A very important step is careful dust removal after each sanding. I don't know of any good way around the final sanding steps for a really good finish. I use my drum sander to get the planer/jointer marks out before starting the tedious part.

[Joe Scharle]

I'm with Art, wipe-on out of the can is what I use when I varnish. However, I almost always put on a sealer coat (Zinnser no wax), then rub it out with 0000 steel wool followed by 400 grit for a baby butt smoothness. There shouldn't be any further sanding required unless there's a lot of dust in the air.

[Dick Mahany]

I too dislike sanding between coats. However, I have seen time after time on woodworking and certain automotive finishes, that it is unparalleled compared to any other method. I'm old school and have resigned myself to do what it takes to produce the best end result. After all, it's only time

[Jim Matthews]

I apply Waterlox with Mirka Mirlon non-woven abrasive pads.

Each layer is applied with progressively finer grits until I get to the desired sheen, and depth of finish.
No sanding between coats required. It's a fully cooked Varnish that seems to penetrate well and forms a water-resistant surface.

I like the fact that it can happen in any well-ventilated space, without special dust management.
The only down side is that it stinks as it cures.

Mike Pekovich covered this extensively in a FWW article, but I use the method as shown by Bob Van Dyke at his CVWWS.

No sanding required!

[Prashun Patel]

Jim, can u elaborate on your method? I am interested in the mir,on pads.

[Jim Matthews]

It's what Bob Van Dyke teaches, I can't claim any of what follows as my own:

Bob recommends Waterlox for lighter colored woods as it has a mild amber tint, and Watco Danish oil applied the same way on darker woods like Walnut.

The final surface is sanded with 220 after scraping or planing - really smooth planed surfaces be hard to cover at the corners as the film dries and pulls back from edges.

Apply the first coat with a coarse Mirlon pad, press down as firmly as polishing wax off a car.
Seal the pad in a ziploc bag when the surface is covered so you can use it again.

I allow a full ten hours for the first application to cure.
After that, apply the next coat when the finish feels dry - not when it's still tacky.

I use the same pad three times, then move on to the next finer pad until I've got the sheen I want.
Each pad abrades a progressively finer scratch pattern, and the Waterlox seems to flow onto the cured layer below.

I doubt there's any of the prior layer dissolved, once cured. If you do apply a new coat to one that's not yet cured, it seems to just rub out with the solvent.
I found the process really forgiving, even my first time out.

It took about four days to get my dining table to an even finish - no sanding required.

270389

[David C. Roseman]

[snip]
It took about four days to get my dining table to an even finish - no sanding required.

270389

That is a seriously nice table, Jim! Is it black cherry? Don't mean to go off topic, but there must be story behind those clear, wide panels. :) Even the breadboard ends are wider than a lot of material available these days.

David

[Steve Limpet]

It seems the consensus is that sanding is a necessary task for a nice finish, excepting waterlox or the like. But I have trouble accepting this. I can't believe that in a production environment, they are sanding product. When I look at commercial furniture, with intricate carvings and moldings, I don't see how they could possibly sand such areas, it would not be cost effective.
So I guess my question is, how is the perfect finish achieved in the in the commercial production environment? :confused:

[Steve Schoene]

In commercial finishing polyurethane varnish is NEVER used. It is only used by amateurs.

There are two part polyurethane finishes that have such strong solvents that they also can burn in to link the coats, but that material requires a full fledged spray booth--in many areas ones that capture the overspray and solvent fumes. Until not too long ago NitroCellulose lacquer was used, and that burns in between coats, giving a chemical bond. That requires a spray booth that doesn't explode (or a shade tree) More modern commercial finishes are also provided with burn in capabilities and also require real spray booth facilities. The answer is, that amateurs just can't duplicate the commercial finish. Now that's not all a bad thing. Outside of the most durable new high tech finishes, oil based varnishes, including polyurethane, are more durable. But they require dramatically more time, both between coats, and time to cure enough to be wrapped and shipped. Naturally, in commerce, time is money.

[Steve Limpet]

In commercial finishing polyurethane varnish is NEVER used. It is only used by amateurs.
.....The answer is, that amateurs just can't duplicate the commercial finish. Now that's not all a bad thing. Outside of the most durable new high tech finishes, oil based varnishes, including polyurethane, are more durable. But they require dramatically more time, both between coats, and time to cure enough to be wrapped and shipped. Naturally, in commerce, time is money.

We have a custom bathroom cabinet that has very well build dove tail drawers, but its all unfinished. I knew that if it were used, it would not be long before it was stained and perhaps water damaged. So I thought I would put a light coat of poly on the insides of the drawers to provide a protective finish.
I bought two types of finish as a test:
1. Varathane Ultra Fast Poly Semi-gloss spray
2. Minwax Fast Drying Poly Semi-gloss Clear spray

The Varathane ambered the finish, the Miniwax was clear
Both apparently caused the wood to swell and the finish after one coat was very rough. The Minwax was much more rough than the Varathane. Both absolutely required sanding.

How do the commercial finishes avoid this issue?

[Prashun Patel]

Don't confuse sanding between coats with prep sanding before finishing.

Sanding between coats doesn't have to be a rigorous exercise. It's a gentle rub down to smooth the surface.

Also, spraying a finish greatly reduces the sanding required - even vs a wiping finish. By eliminating contact with an applicator (brush, rag) you eliminate dust transfer. Further, sprayed finishes are typically thinned vis-a-vis 'applied' finishes, which causes faster drying and less time to trap ambient dust.

On thin finishes, I have not experienced sanding necessary for adhesion.
However, I don't know of any finish available to the home user (oil,water,shellac,laqcuer) that won't raise the grain after the first coat or two. Hence, I always need to rub down after the first or second coat. I can't see how other chemicals in 'production finishes' would fare any better in this regard.