LumberJocks

Help me choose my topcoat...

  • Advertise with us

« back to Sweating for Bucks Through Woodworking forum

Forum topic by RobH posted 2599 days ago 1556 views 2 times favorited 24 replies Add to Favorites Watch
View RobH's profile

RobH

465 posts in 2673 days


2599 days ago

Topic tags/keywords: topcoat finishing

I am building a set of bookshelves for a contractor that I go to church with. I am ready to start on the first staining run (the carcases, fixed shelves, and backs). I usually use polyurethane in these cases. Usually the finishe turns up with some undesirable stuff in it (bugs, dust, etc.). For my own stuff this does not bother me that much. For someone else this really bugs me.

I have not totally dismissed the use of polyurethane, I am just trying to decide exactly what to do. I am also thinking that I could use shellac or a quick drying finish that Jeff Jewitt wrote about (Quick Drying Finish). This is basically a fast drying varnish thinned 50/50 with Naphtha. I have used all of these finishes before and the quick drying finish from Jeff really does dry like gangbusters.

I just need some help thinking this out. Pluses for polyurethane are that is what I have used the most. Pluses for the other two are easy application (I will wipe either shellac or the thinned varnish).

Help me out here,

-- -- Rob Hix, King George, VA


24 replies so far

View oscorner's profile

oscorner

4564 posts in 2935 days


#1 posted 2599 days ago

Rob do you have a deticated room for finishing? Is there a way you can isolate this piece (with a make shift curtain of visqueen) to reduce the amount of dust, bugs, etc.? I have had times, even with shellac that dust will get in to the mix. I just sand with 600 grit, wipe down with a damp clothe to remove all the dust and respray. You can finish with your normal polyurethane, then sand and wipe down and finish with shellac or other quick drying finish. Hopefully this will alleviate most of your trouble.

-- Jesus is Lord!

View Dorje's profile

Dorje

1763 posts in 2621 days


#2 posted 2599 days ago

I like the idea of the Jewitt fast dry finish – (thanks for the tip! – I printed the article). There are those pieces that you just don’t want to take days and days on to finish.

I typically save the poly for the heavy use items, such as the kitchen table. For a bookcase – why do you need the protection the poly would give? And, if you’re worried about what might settle in the poly film finish, then then a wipe on application is called for! I vote for giving the fast finish a shot – they’re bookcases!

-- Dorje (pronounced "door-jay"), Seattle, WA

View TomFran's profile

TomFran

2942 posts in 2618 days


#3 posted 2598 days ago

Personally, unless you have a suitable place to spray a mineral based product, I would stick with lacquer since it dries quickly. That is important for (2) reasons.
  • Lessens the problem of overspray sticking to everything in the vicinity.
  • Less time for dust nibs / bugs / etc. getting in your newly sprayed finish.

Go to Lowes and buy a can of Deft (lacquer). This sprays well and is a pretty good finish. It is also much easier to rub out the finish with steel wool, and if you ever have to repair the finish, it is better for that as well.

Or, you could go to a paint store and buy a can of precatalized lacquer (Campbell) and that will work well too. IMHO

I have had excellent results spraying lacquer, and I don’t have a booth. I have had to spray my large projects in my backyard. Lacquer doesn’t hold up as well for table tops exposed to moisture, but for bookcases or other projects where people are going to be putting wet items on it, it works fine.

-- Tom, Surfside Beach, SC - Romans 8:28

View doyoulikegumwood's profile

doyoulikegumwood

384 posts in 2616 days


#4 posted 2598 days ago

i agree with tom the best finish fo this would be a lacquer it dris fast most in less then hour ready for a second coat in 15 min i meen for something that isnt going to have heavey use its great i even use it on heavy use items i just put on more layers

-- I buy tools so i can make more money,so ican buy more tools so I can work more, to make more money, so I can buy more tool, so I can work more

View WaywardHoosier's profile

WaywardHoosier

80 posts in 2659 days


#5 posted 2597 days ago

I too have been trying to improve my finishing techniques. I am hesitant to spray lacquer because I do not know how how much air pressure to use and what the ratio of lacquer to mineral spirit (thinning agent guess?) should be.

Also, typically how many coats is a good rule of thumb?

Or are we talking about spray cans here? I tend to over think things sometimes.

-- WaywardHoosier - Behind schedule and over budget, but who's counting? Well of course she is!

View Karson's profile

Karson

34869 posts in 3024 days


#6 posted 2597 days ago

Thinner for Lacquer is Lacquer thinner. Not mineral Spirits. Also use it to clean brushes and spray equipment.

I’d go the lacquer route.

-- I've been blessed with a father who liked to tinker in wood, and a wife who lets me tinker in wood. Southern Delaware karson_morrison@bigfoot.com †

View TomFran's profile

TomFran

2942 posts in 2618 days


#7 posted 2597 days ago

”Lacquer doesn’t hold up as well for table tops exposed to moisture, but for bookcases or other projects where people are going to be putting wet items on it, it works fine.” – TomFran quote above

I just noticed a typo on my previous post. It should read “where people are NOT going to be putting wet items on it…”

As to the amount of pressure to spray lacquer, I usually spray it at around 40lbs.

The number of coats will depend on how much you thin your lacquer, but for me, (3) coats is usually just right. You can use your lacquer for your sealer coat and then lightly sand it with 280 grit or finer to smooth it before the next coat. The nice thing about lacquer is that you can complete your finishing in one day. Whereas, with varnish, you should let it sit overnight before applying the next coat.

In all honesty, finishing is just as much an art as the woodwork itself. Some people can build beautiful projects and end up with a lacklustre result because they don’t have their finishing techniques down. A couple of good books on the subject are essential for all serious woodworkers. They are:

-- Tom, Surfside Beach, SC - Romans 8:28

View WaywardHoosier's profile

WaywardHoosier

80 posts in 2659 days


#8 posted 2595 days ago

Tom,

Thank you for the detailed information. I have read an article from Jeff Jewit and have checked out his website of the finishing products that he promotes. I will also check out Bob Flexner’s information as well.

I have never used an air compressor, lacquer, or shellac. But I think I need to start to get that “Furniture store finish” look that will make my projects look more professional and not “craftsy”.

I agree finishing is an art.

-- WaywardHoosier - Behind schedule and over budget, but who's counting? Well of course she is!

View Douglas Bordner's profile

Douglas Bordner

3962 posts in 2687 days


#9 posted 2595 days ago

Ultima Spray Lacquer (waterborne, poly-based). Target Coatings (order online) or through Jeff Jewitt’s Homestead Finishing website (at last order you have to fax in). I have a home shop and used to use MC Campbell Magnalac. Terrible odor, dangerous lacquer thinner based (explosive). I am totally won over to this stuff. You might find it best to spray as much of the case as flat parts and then do the final assembly (mask off the glue joints first with green 3M tape). Target also has pre-cat and varnish offerings, all waterborne. Soap and water gun clean up (don’t use solvents or you’ll end up picking balls of white crud out of your gun). You might check to see if they sell a gun cleaner where you buy yours. I got a product called “The Challenger” at a local independent paint store that works great. Spraying light, 20 minutes dry out of dust, one hour recoat.

If you finish in the flat you can lightly use a card scraper (Veritas sells an Ultra thin card scraper you can bow with one hand and put a gentle hook on just for finishes) to knock off the nibs, scuff sand with 320 grit between coats and shoot 3 coats in a day without blowing up the neighborhood and without the hideous aroma (that draws bugs like rotting fruit) of Magnalac or Deft. This stuff burns into the next coat like shellac or lacquer. I even shoot this stuff in my funky garage workshop, which is none too clean, although I sweep it up about an hour before spraying. General Finishes has a good (and cheaper) waterborne that rated well in Fine Woodworking’s recent test if saving a few buck is important. It just isn’t as heat resistant, but unless you client is storing heated hex nuts (their test material) in his bookshelf, that shouldn’t be an issue.

As far as rubout, look for Mirka Abrasives Abralon pads. They let you rubout to 4000 grit dry with a Random Orbital sander. I use them on my jewelry boxes, posted on this site.

Take a look at a blog entry of mine for links and info
http://lumberjocks.com/topics/549

Or you could just use wipe on BLO/Mineral spirits/Thinned varnish and do an “in the wood” finish or Doug Stowe swears by Deft Danish oil on his boxes.

-- "Bordnerizing" perfectly good lumber for over a decade.

View Douglas Bordner's profile

Douglas Bordner

3962 posts in 2687 days


#10 posted 2595 days ago

Oh. And always do tests on a test board first with any new finish or process before applying to your piece. And TomFran’s literature choices are highly recommended!

-- "Bordnerizing" perfectly good lumber for over a decade.

View TomFran's profile

TomFran

2942 posts in 2618 days


#11 posted 2594 days ago

Doug,
Thanks for the tip on this water-based topcoat. I am very interested in finding a suitable replacement for lacquer based products, but I have a few questions for you.

  • What about the grain raising tendency of water based products?
  • Do you not have to wet the wood and sand off the raised fibers before you can use a water based topcoat?
  • Do you think that the finish is comparable to the lacquer based as to the beauty of the finish?

The grain raising problem creates another step in finishing, doesn’t it?

-- Tom, Surfside Beach, SC - Romans 8:28

View Douglas Bordner's profile

Douglas Bordner

3962 posts in 2687 days


#12 posted 2594 days ago

I use Zinsser Sealcoat de-waxed shellac to seal the wood after P220 grit prep, then rub that with a red or gray non-woven adhesive pad. Just be sure to avoid steel wool as you will get rust flecks that don’t go away. Follow with the waterborne. No grain raising.

Beauty wise, it’s no question at least the equivalent of solvent based lacquer. It is water-white finish, but the shellac sealcoat does warm it a little. Over darker woods, I mix a little amber additive (I add a drop or two of Jewitt’s Trans-Tint per pint measure) which warms it to Nitrocellulose tint. On maple it is simply glorious without additional tinting, preserving the creamy tints of tiger maple etc., while providing the chatoyance (color reversal dependent on visual angle) that one experiences with figured woods. And it doesn’t tend to yellow over time like solvent based Nitrocellulose. I could not be happier with the change from standard lacquer, plus I am allowed to bring it in the house to cure, something none of the other residents will allow here at the Bordner house (especially Magnalac which off-gases with a smell of toxic nuclear bananas for at least a week). Stuff smells like standard Latex paint as it cures.

-- "Bordnerizing" perfectly good lumber for over a decade.

View TomFran's profile

TomFran

2942 posts in 2618 days


#13 posted 2594 days ago

Doug,
  • Do you use an HVLP system with a conversion gun or a turbine?
  • Do you spray your shellac?
  • Does this have to be sprayed with an HVLP system? (I don’t have one – mine is a regular compressor)

I have never sprayed a water based topcoat. I was wondering if it sprays any different than solvent based.

-- Tom, Surfside Beach, SC - Romans 8:28

View Douglas Bordner's profile

Douglas Bordner

3962 posts in 2687 days


#14 posted 2594 days ago

Tom,
I have a conversion gun. I usually don’t spray shellac, but rather pad it on the flat pieces with the glue areas taped off with blue or green 3M tape. I tried spraying one, didn’t find it to be so satisfying (more mess, more explosive risk, creeps up the sides of box interiors, padding seems suitably fast due to the fast drying time. Six boards for boxes can be done sequentially and by the time you finish the last in series the first is ready for next coat. You can get three padded on coats in about an hour.
I think you can use any type of gun, but HVLP has less waste and overspray. Highland Hardware has a ShopFox gun under $50 bucks, or the PC gun at Lowe’s (actually DeVilblis) is reasonable.

-- "Bordnerizing" perfectly good lumber for over a decade.

View woodspar's profile

woodspar

710 posts in 2723 days


#15 posted 2594 days ago

This is great – I did not know anything about lacquer. Thanks all, TomFran, Douglas, esp.

-- John

showing 1 through 15 of 24 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com

Latest Projects | Latest Blog Entries | Latest Forum Topics

GardenTenders.com :: gardening showcase