PDA

View Full Version : Earlex 5500, Lacquer, and Pore Filling advise



Pono
02-07-2012, 05:24 AM
First off I want to say thank you to the experienced builders who post to this forum. Many of the post have been a great help to a novice builder. I built a Stew Mac Tenor kit last summer and I have been working on my first two Koa tenor's from scratch. I have been trying to follow many of Pete Howlett's techniques described in this forum and on youtube. I used an Everett style bender to bend my sides and attempted to copy Pete Howlett's mold for gluing the fronts and backs at the same time (the one demonstrated in the 7 min gluing of the fronts and backs of the Helsinki Tenor).

Not surprisingly I struggled a bit when I finishing the Stew Mac kit. I used Bahlen mahogany pore filler, Bahlen vinyl sealer, and aerosol spray cans of Bahlen Stringed instrument lacquer. I put about 12 coats on waited a month, wet sanded, and buffed. The instrument looked ok but the pore filling was not done well (I had not filled the pores well enough so there were still dimples all over the instrument.)

I am planning on getting an Earlex 5500 to finish these Koa tenors. I have read the threads on this forum and it sounds like one of the main factors in determining whether this unit would work would be the finish that I plan on using. My questions are:

1. Has anyone had success using the Earlex 5500 to finish with lacquer on a instrument?
2. If yes what finish did you use? (is Seagrave (Mcfadden) Lacquer the best by far?)
3. What size spray needle did you use? (most people selling the 5500 right now have a deal where you get both a 2mm and 1.5 mm spray needle. I know that the 2 mm is probably too large but I am not sure if the 1.5 is small enough or I need the 1 mm.)
4. Pore fill with Chemcraft pore filler, or Z Poxy, or Bob Smith Industries Finish Cure?
5. Finish with the neck attached to the body or separate and then glue after finishing?

I was planning on pore filling with Chemcraft medium brown pore filler and then using Seagrave (Mcfadden) Lacquer (I know that Chuck Moore said that the original Mcfadden finish was by far the best) . Seal with the Seagrave Vinyl sealer, pore fill, seal with vinyl sealer, and then coats of lacquer. I have also read a decent amount about the Z Poxy pore filling system but I was not sure how well the vinyl sealer would bond to the Z Poxy. Pete Howlett also mentioned in a post that he uses Bob Smith Industries Finish Cure. I like the idea of the epoxy pore filling but I am a little worried about the process and making mistakes that I cannot fix.

Any help on these topics would be greatly appreciated.

Here is a picture of the Stew Mac kit in the final stages and the new Koa tenor almost ready to begin finishing. I bolted on the neck for the picture but have not glued it yet,
3328333284

mzuch
02-07-2012, 07:14 AM
I have the Earlex 5500. It works very well, but I don't use it much because I don't have a proper spray booth. That means I can only spray when the weather is warm and dry enough to work outside. During the cold months I finish either with Tru-Oil or french polish.

I generally use the Seagrave lacquer with the 1.5mm needle, but a smaller one would probably be better. Try them both to see what you like. In terms of pore filling, I've used two of the products you mention and like Z-Poxy the best by far. It fills the pores quicker and with much less shrinking than the Chemcraft. But you'll probably still need 3 coats to get all the pores filled. Instead of using the vinyl sealer, apply a thin wash coat of shellac between the cured Z-poxy and the lacquer. Finish the body and neck separately; getting into tight corners at the heel and fretboard is a royal pain.

Moore Bettah Ukuleles
02-07-2012, 08:05 AM
With any HVLP, the most important thing to is to thin your lacquer properly. The 5500 may or may not have enough power to atomize correctly but in any event use the smallest tip you can get your hands on. Many of us here in Hawaii have switched to a Sherwin Williams (Hi-Bild) lacquer with very good success. It's high solids content means you can reduce it as thin as 50/50 and still get away with only a handful of coats. Make sure you use a retarder. It'll help with any blushing that may occur as well as allowing some time for better flow out.

Allen
02-07-2012, 09:17 AM
The single biggest thing you will do to get a better job is to add a small amount of retarder to the mix.

When it comes to pore filling, products that are catalysed will have better filling properties to those that rely on drying by evaporation. Those ones will always have a tendency to move on you with swings in RH. And more often than not will sink back just enough on you in a month or so's time after the finish has been buffed up to leave you despondent over all the careful work you did.

As for the other products, I can't comment as I don't use them or they aren't available in Australia.

Rick Turner
02-07-2012, 10:37 AM
I'm now a major advocate of pore filling with a low (or no) amine epoxy. Zero shrinkage under whatever finish you choose. Also, Cardinal is now the go-to nitro lacquer of choice among a lot of pros here in the US. As for HVLP, we use 3M disposable and SATA conversion HVLP guns with the 3M Paint Preparation system of cups with disposable liners. Never going back. The 3 M guns with the disposable caps are incredible for sealers. SATA for top coats. There are viable high quality less expensive alternatives to the SATA guns now, but these are what we have, and at 15 years plus on the guns and thousands of instruments sprayed, they've well paid for themselves. We just rebuild them every now and then with new bushings and packings, caps and needles...and not even very often. I only have to disassemble and clean the guns about three times a month. The PP system is a huge time and solvent saver.

Pono
02-07-2012, 03:33 PM
Thank you for all the feedback. I looked up Cardinal Lacquer and it looks like it could work well. I know that the Cardinal Lacquer come already thinned but how much more do you thin it? Do you use the viscosity cup to tell? What type of retarder do you need to use? Can you use the retarder put out by Seagrave? Rick, what brand low (or no) amine epoxy do you use to pore fill? I will take a look at the 3M conversion guns with the disposable caps. Chuck, I will check out the Sherwin Williams product you mentioned and if I go with the 5500 I will get the 1 mm. Is everyone in agreement that it is best to finish the neck and body separate? If so are there any things that I need to be careful of besides correct masking of the areas to get glued?

Steve vanPelt
02-07-2012, 04:05 PM
When I first got the Cardinal instrument lacquer, I downloaded the finish schedule for their regular lacquer, which says to thin up to 50 percent. Didn't build too well. So I called Mac, Cardinals' technical wizard for advice. He told me to thin no more than 10 percent and up to 5 percent retarder. He said it didn't NEED thinning, but go ahead if you think you need to. I told him I was using Seagrave thinner and retarder, he said that would be fine.

Rick Turner
02-07-2012, 05:10 PM
I am just about to combine two epoxy products based on the best qualities of each using one coat of each.

1) Smith & Co. Clear Penetrating Epoxy Sealer ( CPES ) for popping figure and it's penetration into the wood

2) System 3 Epoxy coating for better pore filling

Both are low or no amine, so there's no interference with catalyzed finishes which I use almost exclusively. The combination and the use of these products actually stiffens the wood allowing you to build thinner...interesting conversation with Ken Parker about this at NAMM after hours at hotel room. The epoxies don't shrink once cured. They enhance the stability of the wood. They can be topped with an oil finish...TruOil or Waterlox...Ken's $30,000.00 archtops are now finished with two coats of epoxy lightly sanded with two coats of TruOil on top. Of course you can do any kind of lacquer, urethane, or polyester finish on top of the epoxy.

NO, you won't get the traditional Martin dark porefilled look that also stains the wood unless you use water based pore filler and then epoxy on top of that...which is a very good alternative.

The Cardinal guys know more about using their products than any other paint company reps I've met, although they don't have quite the polyester finishes I like. Still, they are really good folks who have worked really hard to come up with the right combination of attributes for guitar lacquer finishes. They blow Seagrave completely out of the water.

Chris_H
02-09-2012, 05:16 AM
I have sprayed many thousands of gallons of lacquer and quite a few different types. I am currently using the Sherwin Williams Hi-bild (not spraying too much anymore though, mainly polishing and oiling myy turntable plinths) The Sherwin Williams lacquer is about the easiest to spray and friendly to work with that I have encountered yet. Gun choice is important too. I am using an Accuspray HVLP with pressure cup. It is one of my favorite guns ever, and ironically I found it at the local Habitat for Humanity store for $15, looked like it had been used once and put away dirty. A detailed cleaning brought it back to new. The lacquer needs to be carefully strained every time. I do thin with acetone most of the time.

Chris_H
02-09-2012, 05:23 AM
I'm now a major advocate of pore filling with a low (or no) amine epoxy. Zero shrinkage under whatever finish you choose. Also, Cardinal is now the go-to nitro lacquer of choice among a lot of pros here in the US. As for HVLP, we use 3M disposable and SATA conversion HVLP guns with the 3M Paint Preparation system of cups with disposable liners. Never going back. The 3 M guns with the disposable caps are incredible for sealers. SATA for top coats. There are viable high quality less expensive alternatives to the SATA guns now, but these are what we have, and at 15 years plus on the guns and thousands of instruments sprayed, they've well paid for themselves. We just rebuild them every now and then with new bushings and packings, caps and needles...and not even very often. I only have to disassemble and clean the guns about three times a month. The PP system is a huge time and solvent saver.

Rick, I am curious what type of epoxy you are using. I use epoxy under automotive finishes on wood, to prevent the finish from shrinking back into the pore structure over time, Raka epoxy, two very thin coats with sanding, but then it is top coated with an automotive primer. Is nitrocellulose picky about what epoxies it will adhere to? Also, epoxy soaks very deep into wood, this definitely affects the acoustic properties of wood, especially thin wood. Have you noticed any difference in sound between the epoxy filled, and non epoxy filled finishes?

Chris_H
02-09-2012, 05:44 AM
Oh, I see I missed your other post Rick, questions answered.

I looked at the Earlex 5500 online. Personally I would stay far, far away from any finishing supplies marketed as DIY or Home. More often than not these products will almost never allow a proper finish. The Accuspray model 10 is awesome, if you have a decent compressor, and be sure to use an inline air filter of the type that attaches to the base of the spray gun handle. Or, the Graco 4900 complete HVLP system is quite versatile, I also own one of those. You can probably pick up a used on on ebay for a reasonable cost, one that someone used once or twice and is selling. That systemcomes with 5 different fluid needle/tips. It will happily spray from anaine dyes up through textured speaker coatings that are nearly the consistency of caulking.

Moore Bettah Ukuleles
02-09-2012, 06:41 AM
I had an Earlex for a very short period of time. I quickly upgraded to a Fuji Q4. It's got enough power to atomize correctly. What I like about the HVLP is no contamination from a compressor, less lacquer used, and the atmosphere in the spray room is clearer.

Chris_H
02-09-2012, 07:19 AM
The Q4 is a very good unit, comparable to the Graco 4900. The Accuspray Model 10 is an HVLP gun, so it does not overspray considerably more than a turbine HVLP, nowhere near a conventional gun. I use a Sharpe Air control unit, and the small disposable inline gun filters, never have had any air contamination issues except for the occasional time when spraying a lot and finish makes it into the air chamber, dries, flakes off into the spray stream. That is operator error and happens in the turbine system also. In a production shop, with the air plumbed in copper pipe, sloped with drains and valves, the air controller really only adds redunduncy ( which is good!) I own several HVLP guns that run from compressor, several conventional guns, and the 4900 with 2 guns. The Model 10 is the only HVLP non turbine gun that I really like (so far) For lacquer, the Accuspray wins hands down, beats anything I have ever sprayed lacquer with, except maybe airless in some higher production instances not applicable to limited production instrument finishing. For dye or stain, the Graco wins. For thick stuff, the Graco works well though an airless is best for thick coatings. For lacquer, the Model 10 with the pressure cup, or for slightly higher production, a 2 qt pressure pot, is my choice. The Model 10 with a 2 qt pressure pot would be an ideal rig for spraying instruments.

Pono
02-09-2012, 11:30 AM
It sounds like the Earlex 5500 might not be powerful enough to get good results. Chuck, it sounds like you just were not happy with the 5500 and needed to go to the Fuji Q4. I was not planning on spending too much for the spray set up. I will take a look at the HVLP conversion guns. I have a compressor but was hoping to go with a turbine system and not a conversion gun. I will have to check the specs on the compressor. Earlex makes a 6900 is more powerful and not that much more expensive that might be an option but I do not think that the Graco 4900 or the Fuji Q4 are options because of the price. Thank you all for the feedback. I have some thinking to do.

Chris_H
02-09-2012, 12:13 PM
DIY spray guns, and finishing tools will almost never yield professional results (meaning the results will likely be noticeably be inferior) Finishing is tricky enough to begin with, with all of the proper elements in place. French polishing with shellac is traditional, it can be learned, and is beautiful. Spraying with crappy spray gear is worse than sitting between two sick people on an airplane. Used good tools (purchased through craigslist or ebay, be careful and ask questions) will hold their value. DIY spray gear purchased new never had any value, so if you ever decide to get rid of it, it will be to goodwill. Many painting contractors are changing careers in the reshaping economy, so used, excellent spray gear at good prices is frequently available. The Fugi Q4 or Graco 3800/4900 will serve you well, and be a pleasure to use. If you only need this for finishing ukes, the Accuspray model 10 sprays the Sherwin Williams Hi-bild beautifully, 'like buttah...' It sprays a wide range of finishes like that actually. You need a decent size compressor for this gun, not huge, but not small, like the larger of the small contractor compressors. IMO, looking at it from a budget standpoint, if you want to play, you have to pay, at least a little bit. Stay away from DIY stuff if you want to walk away from a freshly sprayed piece, looking at the 'glass' and smiling... If you cannot afford spray gear, I would learn to French Polish. Shellac is really cool stuff.

Rick Turner
02-09-2012, 01:05 PM
Tru Oil over epoxy is a viable finish if you don't need high gloss...it works for Ken Parker on $30,000.00 archtops. French polish over epoxy is another alternative.

Moore Bettah Ukuleles
02-09-2012, 01:56 PM
Tru Oil over epoxy is a viable finish if you don't need high gloss...it works for Ken Parker on $30,000.00 archtops. French polish over epoxy is another alternative.

Doesn't the Tru-Oil need periodic maintenance like FP does? Don't know, never used the stuff.

Chris_H
02-09-2012, 04:00 PM
Tru Oil over epoxy is a viable finish if you don't need high gloss...it works for Ken Parker on $30,000.00 archtops. French polish over epoxy is another alternative.

+1
forgot to mention about oil... Oil over epoxy is good too. The key to an excellent finish here is sanding, at least to 1000 grit, and to 3000 or more if you want. 3000+ will bring a pretty full on gloss, though you will need a buffer. Aesthetically, oil over epoxy will have an edge on a straight lacquer finish when color is concerned. Many woods will not develop to their full color potential under lacquer, especially darker woods like Koa, or Mahogany.

If you lack spray skills, shellac or oil might be a good idea. There is a steep learning curve to lacquer, and especially polishing lacquer.

Rick Turner
02-09-2012, 05:18 PM
Yes, Tru Oil or Waterlox will need periodic refreshing...or you just let it go to a patina. Whole other thing than dead flat high gloss finishing, but much easier to do without a major investment in spray gear and a booth and big time buffing equipment.

blues
02-10-2012, 12:30 AM
Is there a clear winner between the Graco 4900 and the Fuji q4?

Chris_H
02-10-2012, 01:30 AM
Graco is a name that is ubiquitious in the finishing world. Every paint store I have ever been in carries Graco, which means that parts are possibly more readily available. They are both 4 stage turbine powered. I do not know the filtration system on the Fuji. They are probably both comparable. I would buy the 4900 again... unless of course I was spraying waterbornes or lacquer, then hands down I would buy the Accuspray. Getting an 'out of the gun' acceptable finish is not always an easy thing, and the application equipment is a big factor here. Polishing is easier following a great spray application. As far as the compressor, yes they are big, but pneumatic sanders and polishers trounce all over the electric sort, which is a reason in itself to have air in the shop.

Pono
02-10-2012, 01:51 AM
So if you were spraying only lacquer (also shellac for a sealer coat) on ukuleles you would go with the Accuspray model 10 gun with a compressor over the Fuji Q4 or the Graco turbine systems? This soulds like what you were saying but I wanted to make sure.

Chris_H
02-10-2012, 02:24 AM
Yes absolutely. Gold anodized air cap says 807, fluid tip says 61. Shellac is very easy to spray, most any decent spray rig should work fine. Lacquer is a different story. Every lacquer handles slightly different. If you are spraying one or 2 at a time, the gun mounted pressure cup will be fine. If you are spraying production, a 2 qt Binks pressure pot with a 5 - 10 ft air/ fluid hose is awesome. For succesive coats on the same day you can just give the pot a swirl and keep spraying. At the beginning of a new day, a good swirl of the pot, turn the air nozzle at the gun, off, and flush the hose back into the lacquer can. ready to spray again when the hose is flushed. No need to empty the pot at the end of the day. Keep the insides of the cup operating room clean, and strain everything that goes in. You will need a decent size compressor. You should still be able to pick it up and carry it, but the small pancake types will definitely not work. Having a separate pressure pot also gives much more mobility which will increase your spray accuracy.

Shellac is a good sealer for lacquer, though you need to be careful with the sanding dust as lacquer will not melt shellac. Shellac will go a long ways to bringing out the color in wood. Shellac gives out excellent holdout under lacquer. Straight lacquer over Koa, or Mahogany, IMO, ruins the wood color wise. If I am spraying lacquer over one of these woods, or a Rosewood, coating the piece in Benite, or similar, first, then shellac, then lacquer, will yield the best color over time. Spraying too thick a coating of shellac, or not letting it dry sufficiently can cause problems. For some Rosewoods, an initial coat of Benite, with a small amount of Japan drier can help offset the effect of the natural resins in the wood and their interaction with the finish.