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Moore Bettah Ukuleles
09-06-2011, 06:49 PM
At the end of a month's building cycle I'll spend days hand sanding ukes getting them ready for buffing. My standard procedure usually includes Mirka grits 1000, 1500, and 2000, all wet. Sometimes I'll follow it with Micro Mesh 3600. Then it goes to the power buffing stage. After hand sanding several hundred instruments I got Popeye forearms.
Today I decided to use the Abralon discs I've had sitting on my shelf for years with my random orbital sander (slow setting). I decided to resand and rebuff an old uke of mine. I used grits 1000, 2000 and 4000. First I tried them dry and the result was an egg shell-like texture. Probably getting too hot. Then I tried it wet (the foam backing absorbs water) and I think I like it. It sure is quick and the 4000 makes the buffing pretty easy.
Has anyone else used Abralon on lacquer? I think John Greven does but I could find no information to substantiate that. Any tips? Any sand-throughs?!!!!
By the way, I'm not just looking to achieve a shiny surface. I like a wet, glossy, mirror-like finish. I'm able to get it by hand but this old guy's getting tired!
Thanks.

olgoat52
09-06-2011, 08:13 PM
Wow! that's some fine grit. We used to stop at 600, let it harden and then buff. Can't imagine going to 2000 much less 4000. My chisels don't get it that good. ;)


At the end of a month's building cycle I'll spend days hand sanding ukes getting them ready for buffing. My standard procedure usually includes Mirka grits 1000, 1500, and 2000, all wet. Sometimes I'll follow it with Micro Mesh 3600. Then it goes to the power buffing stage. After hand sanding several hundred instruments I got Popeye forearms.
Today I decided to use the Abralon discs I've had sitting on my shelf for years with my random orbital sander (slow setting). I decided to resand and rebuff an old uke of mine. I used grits 1000, 2000 and 4000. First I tried them dry and the result was an egg shell-like texture. Probably getting too hot. Then I tried it wet (the foam backing absorbs water) and I think I like it. It sure is quick and the 4000 makes the buffing pretty easy.
Has anyone else used Abralon on lacquer? I think John Greven does but I could find no information to substantiate that. Any tips? Any sand-throughs?!!!!
By the way, I'm not just looking to achieve a shiny surface. I like a wet, glossy, mirror-like finish. I'm able to get it by hand but this old guy's getting tired!
Thanks.

Michael N.
09-06-2011, 09:57 PM
I don't know about Lacquer. For a gloss type finish I use brushed on Spirit varnish. It always surprises me how long some people rub out the finish. I'm done in about 20 minutes but then again I don't go for the super shiny finish. I've even come across some who claim to spend 40 hours just on French Polishing one Guitar!
olgoat52. You stop at 600? That's my starting grit, sometimes 800. Finish at 1500 before using a liquid burnishing cream.

Moore Bettah Ukuleles
09-06-2011, 10:13 PM
Wow! that's some fine grit. We used to stop at 600, let it harden and then buff. Can't imagine going to 2000 much less 4000. My chisels don't get it that good. ;)

My finishes look better than your chisels! :)

Moore Bettah Ukuleles
09-06-2011, 10:16 PM
My finishes look better than your chisels! :)

Actually, it isn't at all uncommon to go up 2000 or higher prior to buffing. In fact if you wanted to do it all by hand you'd work all the grits up to 1200 with Micro Mesh.

DeVineGuitars
09-07-2011, 01:26 AM
Hey Chuck, Do your self a HUGE favor and use the 3m finishing film.
After my 3 days of building and leveling I sand with 1000 or 1200 3m (dry) and a quick 2000 abralon. That's it. I have not wet sanded in years and will never do it again. Call me if you like and I can fill you in on the details.
Ps. I'm also using a new lacquer from cardinal that I think is even beter than Mcfadden.

Moore Bettah Ukuleles
09-07-2011, 07:24 AM
Hey Chuck, Do your self a HUGE favor and use the 3m finishing film.
After my 3 days of building and leveling I sand with 1000 or 1200 3m (dry) and a quick 2000 abralon. That's it. I have not wet sanded in years and will never do it again. Call me if you like and I can fill you in on the details.
Ps. I'm also using a new lacquer from cardinal that I think is even beter than Mcfadden.

Thanks Eric. Someone just gave me some of those 3m discs to try but I haven't done anything with them yet. I'll have to do some research. I assume you are power sanding with the 3m discs. How are you sanding with the Abralon?
I have not heard of cardinal lacquer. You getting that locally?

Frankie2blue
09-09-2011, 12:43 PM
I have always used the Micro mesh wet sandpaper on either a closed cell foam pad or a small piece of corona as a block. Starting with 1800 then 2400 and finishing with 3200. I mix just a bit of dish soap in the water for a lube and it has always worked out great. Takes very little work to buff to a mirror after that.

Tudorp
09-09-2011, 12:50 PM
I typically stop at 1500. I have some 2000, that I do go to every so often, but not much. I used 2000 on my Gibson Les Paul restoration, and it came out very nice. I could imagine the wet look finish you can get going to 4000.

Moore Bettah Ukuleles
09-09-2011, 01:27 PM
4000 grit will give you a satin finish. You need to get up to at least 10,000 to 12,000 for a wet look. I'm talking about a reflection you could shave with. I Know this sounds ridiculous and a bit extreme to some but mirror finishes is what I do and it's a trap I've found myself in.
The drawback with Micro Mesh is the cloth back gives you too much cushion. It rides over the orange peel rather than flattening it. Of course you can start with a coarser grit but then you're sanding forever to get those scratches out. Now I hand level the surface with 1000 Mirka wet backed with a very dense foam block.
I build a lot of ukes and I can't be doing this by hand anymore. Yesterday I had fabulous results with the Abralon (wet) and a random orbital sander. My finishes are better now spending 25% to 30% of the time previously spent doing it by hand. Just don't know why it took me so long to get here! Stupid. Got some 3M finish film (260L) on order.

Allen
09-09-2011, 09:30 PM
It can get confusing to some not familiar with sandpaper and abrasives by quoting grit numbers without also including the grading system, as they are not all the same. Even from brand to brand there are variations in the scratch pattern using the same grading system.

For most companies the grading is done with the P as the prefix, and is what most people associate with. Therefore when you say P180 you have an idea of the grit size in relation to P600 or P1000. There are other companies and products out there that use other systems and the grit numbers do not cross over in any meaningful way, so beware.

As a side note, wet and dry grades always give a scratch pattern that is coarser than what you will get in a dry paper. It's the type of grit and glue that is used. So for instance if you were to want a finish of P800 dry you would need to use P1000 wet. You also get a finer finish using the exact same grade of paper when using a random orbital as compared to a block by hand.

And for levelling a painted surface you have to use around P320 - P400 dry or P600 wet to start off. That is to take our runs, orange peel etc. Anything finer just refines what is there. Once the surface is level you move through the grits, never jumping more than P200 each time until you get to P1200. Then it can be larger jumps of P500 at a time. Remember the next grit is only refining what was there previously, so you are removing the coarser scratches and leaving finer ones. NOT removing imperfections, runs, orange peel etc. Keep going through the grits until you get to the level you are happy with. These sandpapers are quite expensive, so you have to decide where to stop for your circumstances.

When I do a gloss finish which unfortunately is most of the time as well, you can easily shave in the reflection.

I never sand past P1000 wet as it doesn't make a lick of difference to my finish or the time spent. Always sand by hand, and it sure doesn't take long to get there. Reason that I stop there is that the way I buff takes only 1 to 2 passes with the buff to get a mirror finish. I could spend more money on sand paper and time sanding and still require that 1 to 2 passes with the buff. I think you can do the math.:)

Moore Bettah Ukuleles
09-10-2011, 10:06 AM
Good comment Allen. I may have confused some people by mixing grit equivalents. Myself included! It can be pretty confusing. It's little wonder the world is constantly at war when we can even agree on something as simple as sandpaper grading.
What are you using as a buffing compound? I'm using Menzerna dry sticks. Fine if I sand pretty high. I like to keep the buffing to a minimum as too much time on the wheel and heat can ruin a finish. I've stopped using the very fine lately as it doesn't seem to do anything more than the fine does.

Rick Turner
09-10-2011, 10:57 AM
We do 95% of our sanding on poly finishes dry, and we don't go past 1,200 before using a couple of different Menzerna compounds on big stationary wheels. Works well for us.

Allen
09-10-2011, 12:48 PM
At home I use Autoglym 03B. It's a medium cut paste used in the automotive trade. At work we've switched to Mothers heavy duty cut. Both are about the same grit but we've found that the Mothers works better. They both have a abrasive that degrades under use. That is to say it breaks down and becomes finer. I'll switch to Mothers when the Autoglym runs out.

Both of these products are to be used on foam buffing pads, not the large rag wheels that seem to be prevalent in the instrument industry. You can use them by hand but doing so will fall into the first way I describe of buffing.

There are a couple of ways to buff a finish out. I'll describe each as best I can.

The first and the one I think most people are doing in trying to get a mirror finish is to attempt to progressively remove the peaks and valleys of the scratch pattern caused by sanding. First by going through progressively finer sand papers and then abrasives. Their goal being to get a scratch pattern so fine that to the naked eye it doesn't exist. This is a very labour and product intensive way of going about it.

The other way, and the one that I use is to get a scratch pattern that is suitably fine enough, then move the top of the peaks to the bottom of the valleys with heat caused by friction. This is dead easy to do with thermo plastic finishes like lacquer. More difficult on catalysed finishes depending on the finish in question and how fully cured it has become. For those who've worked in an industry with catalysed finishes and had to do any buffing you'll know what I mean. If you catch a finish at the right time it's easy to buff out, but after a time the finish becomes so hard that you then have to resort to the first method.

There are a couple of tricks to getting this method to work quickly and efficiently. The first is to use just a very little product on the foam pad and use the heat generated by the friction of buffing across your scratch pattern to move the finish. That is to say take the tops off the scratch pattern and move it into the valleys. If you use too much product then all you are doing is smearing it around and making a mess. It won't start to create the heat you need until the buffing compound has started to dry out.

The other trick is to control the amount of heat caused by the friction of buffing. A little is good. Too much is going to ruin your finish. You need enough that the surface will feel very, very warm to your hand, but NOT HOT. It takes practice but isn't hard to master. Do a little and then touch the surface to get an idea of where your at.

Where I see inexperienced people go wrong in buffing is not understanding the friction / heat issues. Edges need to be avoided as it's incredibly easy to burn through since you have all that heat building up in a very small area. Edges have a way of getting buffed out if you just come up to them. You need to be aware that the outside edge of a buffing pad is moving much faster than the centre so creates much more heat and friction, making it easy to burn as well. Watch what you are doing.

Hope that helps some of you trying to work this stuff out.

Rick Turner
09-10-2011, 04:25 PM
With nitro lacquer, buffing actually slightly melts and burnishes the finish for that final shine. With poly, all you can do is go for finer and finer scratches like polishing glass. These are two major differences in the finishes when it comes to working with them.

DeVineGuitars
09-11-2011, 08:20 AM
Thanks Eric. Someone just gave me some of those 3m discs to try but I haven't done anything with them yet. I'll have to do some research. I assume you are power sanding with the 3m discs. How are you sanding with the Abralon?
I have not heard of cardinal lacquer. You getting that locally?
I do some light power sanding on the larger areas and hand sand all the rest. Same with the Abralon. The abralon stuff is great but as you mentioned, because of the padding, it does not level enough. That's why I only use it for the last pass.
As for the Cardinal Lacquer, I did a bulk order with Steve Grimes for about 15 gallons (mixed lacquer, thinner, fillers, ect.) but we are working on getting it in Hawaii. Should be fairly soon. This stuff is just what I have been looking for. It blows the doors off of Mohawk and is as good or better than the old Mcfadden.

Kekani
09-11-2011, 10:34 AM
As for the Cardinal Lacquer, I did a bulk order with Steve Grimes for about 15 gallons (mixed lacquer, thinner, fillers, ect.) but we are working on getting it in Hawaii. Should be fairly soon. This stuff is just what I have been looking for. It blows the doors off of Mohawk and is as good or better than the old Mcfadden.

Eric, please keep us informed of this. I know there are more than a few other that should be keeping an eye out.

DeVineGuitars
09-12-2011, 07:52 AM
Cardinal will ship out by the gallon. It's a bit more expensive but worth it. It really is that good.

mketom
09-12-2011, 10:48 AM
Thanks you guys for sharing these finely tuned finishing techniques! More good stuff in this post than I could imagine asking all the right questons about. 4 master builders, 4 different processes! And thanks for those Popeye arms, Chuck! I am still pleasantly amazed at the depth and clarity of the finish on my MB soprano.