Shellac Newbie - Spray & Pray

I've never used shellac before, and I need some advice. I'm finishing a set of bunk beds for my kids, and I want to use shellac as the finish, "blonde" shellac in particular. I'm in a time crunch, so I have to be able to apply it quickly; I'm planning to use an HVLP conversion gun for this. I've read that spraying shellac is tricky.
What # cut should I use for spraying?
Will I need an additive to minimize "fat edges" or improve flow-out if I spray?
Do I need an additive to slow the drying time down if I spray?
How many coats are "normal" for a sprayed shellac finish? I am mindful that the bunk beds will go to some rambunctious boys.
Any help from those who have navigated the minefield before me would be greatly appreciated.
TIA for the replies,
Dave
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Not an expert on either shellac or spraying, but just finished spraying a large project with shellac the past two weekends.

I used 1# cut through a cheap HVLP sprayer and it worked well. FWIW, I used 'off the shelf' BullsEye amber.

I thinned from 3# cut to 1# cut with 99% isopropyl alcohol to minnimize blushing (relative humidity here was in the 90's) and orange peel. I had no problem with denatured alcohol from the BORG during test of the spray gun, but went with the isopropyl on the project itself with good results ... I believe it may have given me a bit more drying time.

I would say that would depend upon a number of factors, including your climatic conditions when you go to spray. You may find that the 99% isopropyl is sufficient. Do some test spraying first to get your mix and technique matched to the current conditions.
From my recent experience, technique is a big part of insuring that you aren't spraying dried, atomized shellac that will orange peel. Most critical thing for me was maintaining a uniform distance from the work piece and not spraying in an arc. Starting the gun off the work piece and keepin it on past the work piece was also important for me.

You will be surprised how many coats you can spray in one day. I sprayed the first coat lightly, went over the project _lightly_ with 600 grit about an hour later, then three more coats at intervals of about two hours each ... i could have kept going, but the finish was what I wanted after four coats.
Each coat on the 42" X 25" X 84" project took less than five minutes.
If you get white dust when you rub out, you can just about bet that the shellac is dry. It has been about a week now and I just went over the entire project lightly with 1200 grit sandpaper and came up with a lovely, and very smooth, finish.
Good luck ... and let us know how it comes out. Hope this helps a bit.
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I just have to throw this in here:
Once mixed with alcohol, shellac starts to esterify which reduces it's film hardness, ability to dry quickly and water resistance. Therefore it is always best to mix it fresh from flakes. Dewaxed flakes are easiest to use (the wax that is naturally in shellac is usually considered an impurity.) Shellac's reputation has suffered in the last few decades from the bad experiences people have had while using old, pre-mixed shellac from the can (along with the hoopla about polyurethane.) They've only recently started to date the cans and claim a three year shelf life while most finishing authorities start to worry about their shellac mixture after about six months. Shellac is a beautiful, non-toxic, easily applied, durable and repairable finish that is at it's very best when fresh.
A shameless shill (but still good advice) from another happy shellac pimp.

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Ron Hock
HOCK TOOLS -- http://www.hocktools.com and http://www.hockfinishes.com
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Bill Wallace wrote:

I doubt if any finish would hold up. Shellac is the easiest to repair.
-- Jack Novak Buffalo, NY - USA
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yeah, I can see him pulling his kids beds out from under them for frequent touch-ups. Why not go with a durable finish and leave it at that? Less headache.
dave
Nova wrote:

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I doubt the boys will notice or care about scratches...when they're done with the beds a light touch-up sanding and a new coat of shellac and you've got a good garage sale item with minimal amount of work...
my 2cents..
Doug
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as you might have noticed I reposted to Dave, since he explained the project more completely. and I'd spray the shellac too.
dave
Doug wrote:

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Many, many thanks for the advice.
To answer some of the questions that were raised and to clarify a little, my first choice for the bunk beds was wipe-on poly. It's easy to apply, and I've had very good results. However, the wipe-on poly would present several problems:
Time: I've found I have to put on at least four or five coats to get the equivalent of 2 or 3 brushed coats. The beds are Mission/Arts & Crafts style with lots of slats; it would take a while to get one coat on, let alone 4 or 5 with either poly or shellac. I could spray poly, but I am left with the impression it would not be as easy to correct newbie HVLP mistakes as it would be with shellac.
I used poly on the crib and, although it is wonderfully durable, warm finish, repairs are difficult (lots of teething marks).
Because I'm pressed for time, off-gassing from the poly curing is a concern. I went through this with the crib.
I chose shellac for the following reasons:
It offers enough protection to keep crayon art from becoming a permanent decoration.
Time: I can apply more coats in less time, particularly if I spray.
It dries quick without the noxious off-gassing.
It's easy to fix if I screw up spraying it.
The beds are made of ash, so it's likely the only thing that will ever get damaged will be the finish.
I'm not inclined to experiment with mixing my own shellac at this point due to time, although I'm sure that's part of the fun of using it. I'm leaning toward's Swingman's suggestion and getting some pre-mixed "clear" BullsEye off the shelf (June '03 manuf date at the BORG last I checked - yes, knowing shellac has a short shelf life, I checked) and thinning it 1:1 with some denatured alcohol to spray.
I realize this could become a glorious fustercluck given I've never sprayed a finish before, but shellac seemed to be the best finish to spray in this case.
Should I take the hit on time and just use wipe-on poly? You guys got me second guessing myself....
Dave
On Thu, 31 Jul 2003 00:47:13 -0400, Dave wrote:

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Dave,
Now that you described the project, I see your reasoning for spraying on the shellac. I've never done it, but I've heard, and fully believe, that spraying poly is an ungodly mess, as it sticks to everything it lands on. I'd now vote with you to go the spray shellac route and if the kids are old enough to understand, ask them to be gentle on the beds. (yeah, right, like they are gonna listen <g>). Doing multiple coats of finish on slats would be a RPITA, if not sprayed.
dave
Dave wrote:

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Dave wrote:

I just mixed my first batch...couldn't be easier. Takes several hours for the flakes to dissolve completely - I left it and completed the mixing process the following day (stirring occasionally).

So why spray? According to Flexner, it can be brushed on...that's what I'll be trying!
************************************ Chris Merrill snipped-for-privacy@christophermerrillZZZ.net (remove the ZZZ to contact me) ************************************
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I wrote:

Sorry, I mixed up this shellac thread with the other one...
************************************ Chris Merrill snipped-for-privacy@christophermerrillZZZ.net (remove the ZZZ to contact me) ************************************
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On Fri, 01 Aug 2003 00:55:19 GMT, Chris Merrill wrote:

Time. It's quicker for me to spray two headboards and two footboards with a total of 60 slats than it is to try to brush them.
Dave
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Spray away Dave. It sounds like you have it all worked out. Shellac is super user friendly. Spray it thin and try to get an adjustment and rate that allows you to do single overlapping passes. Resist the urge to over spray to try and flatten it out. Just lay down enough on the first pass. Also try to use a sequence that will minimize overspray onto areas that have already been sprayed.
Finally, if you get any runs or sags, just wipe them down a few hours later with some alcohol on a lint free rag before re spraying them.

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