Finish Sanding?

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Bob Connor
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Finish Sanding?

Post by Bob Connor » Sun Oct 28, 2007 9:36 am

How do you blokes and ladies rub out your finishes?

Dave and I have been using the hand sanding method with a block and 2000 wet and dry and then finishing up with micromesh pads up to 12000 grit. (on sprayed Ubeaut Hard Shellac)

Whilst the finish is pretty good you can still see little swales and dips if you really inspect it closely and I want to eliminate that.

I've been considering a Festool ETS 125 EQ. Expensive little number here in Oz (^$400) but the 110 volt ones in the States are only $165US and we've got a 110 volt transformer in the shed. (Dave is from Wales and all site tools in the UK have to be 110 volt for safety reasons and he bought it out with him and we forgot that we had it :? )

I really don't want to go down the track of upgrading the compressor to handle Dynabrade air sanders and the Festool seems like a workable alternative.

Any suggestions and comments would be most welcome.

Bob

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Post by kiwigeo » Sun Oct 28, 2007 10:50 am

Hi Bob,

You could try finishing off with Macguires swirl remover. Ive used this on a KTM finish which I sanded back using micro mesh.

Man thats a big price difference on the Festool. How much of that is profit?

Cheers

Martin

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Bob Connor
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Post by Bob Connor » Sun Oct 28, 2007 10:58 am

Hi Martin

We do use Meguires after medium and fine Menzerna for buffing.

What I'm looking for is the initial sanding after spraying.

Cheers

Bob

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Post by graham mcdonald » Sun Oct 28, 2007 12:17 pm

600 and 1200 wet&dry then Brasso, but there is almost certainly a better way!

Be a bit careful with the Hard Shellac. I sprayed a carved mandolin and then one day it crazed all over the body. I showed it to the Ubeaut folks at the Sydney Woodworking show and after they finished laughing they reckoned it was too thick and the tensions set up by the cross-linking stuff they use to make it hard caused the crazing.

cheers

graham
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Allen
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Post by Allen » Sun Oct 28, 2007 7:52 pm

I'm using Mirotone Gloss Catalyzed Lacquer over WEST Systems Epoxy for pore filler. The last Cutaway only required 2 sessions in the spray booth. 5 coats of 50% thinned lacquer each time.

Let dry 2 weeks between sessions. Rub back after 1st spraying with a very firm sponge block with P320 dry paper. Don't cut through if at all possible. The reason to use dry is that it is so much easier to see what you are removing than with wet paper.

Usually the second spray session the finish looks really good. Could almost walk away from it without buffing if you don't mind that type of finish. If you want high mirror gloss, then rub back starting with P600 wet or P400 dry with the same very firm backing sponge block. I only sand until the gloss comes off evenly, NO MORE. This is where you are leveling the surface. Then proceed through your grits up to P2000. Then buff with whatever method blows your fur back.

A note about leveling a surface. It just can't be done with fine papers. You have to use the coarser grits. The finer ones just refine the surface. Also P600 wet abrades the surface equivalent to P400 dry. Thats why the first sanding of the first spray session is with P320 dry and the first paper to see the finish on the second spray session is P600 wet or P400 dry.

Also, the Festool is a beautiful tool, and yes we are being gouged big time for them here. The fine grits used dry are really good. I alway finish up with a final rub with wet paper though. It just does something to the surface to give that little extra "finish".

And I'm ashamed to say I don't own one for at home, only at work. I don't want to bring them home all the time to use them for guitars. But I gotta put one in the budget :wink: .
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Bob Connor
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Post by Bob Connor » Sun Oct 28, 2007 8:52 pm

Graham - we've finished 10 instruments this year with the Ubeaut Hard Shellac and haven't had any problem. (touch wood)

Was it Neil Ellis you were talking to at the woodworking show?

He's the owner and inventor (I guess) of the hard shellac. I've had a few discussions with him about the product and he's always been down to earth and pretty up front about what it will and won't do. So I'm surprised if you got a reaction like that from him.

I did ask him what the finish would be like in ten years time and his answer was "I don't know - the product isn't that old yet". So only time will tell.

How long was the finish on the mando before it crazed?

Bob

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Post by Bob Connor » Sun Oct 28, 2007 9:07 pm

Allen wrote:I

A note about leveling a surface. It just can't be done with fine papers. You have to use the coarser grits. The finer ones just refine the surface.
Thanks Allen

I think that is the information I'm after that I'm missing.

Thanks heaps. I've got one to finish sand in about three weeks so I'll report back.

I still want one of those Festool sanders to do the job with.

Is there any of our American friends who'd be willing to post one to me if I send them the money. We can't order Festool from American commercial websites in Australia. Some protectionist nonsense I believe.

We can't buy Elixir strings here from anywhere in the States for the same reason. :evil:

I tried to get some from Elderly Instruments a month or so ago and got knocked back. Received a nice apologetic email stating that it is Elixir's policy not theirs.

We pay around $40AUD for a set of Elixirs in Oz. From Elderly $12.95USD.


Bob

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Alain
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Post by Alain » Sun Oct 28, 2007 11:57 pm

Yep, Allen beat me to it. Don't be afraid to use coarser grits if you're looking to level the surface...

I used nitro on my latest and my gun wasn't the best quality and the results weren't stellar... If I remember correctly, I started sanding with ordinary paper (the non wet-dry kind) at around 150-180 grit. Of course, you'll take much more off and care must be taken not to sand through.
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Post by Dennis Leahy » Mon Oct 29, 2007 1:47 am

bob wrote:I still want one of those Festool sanders to do the job with.

Is there any of our American friends who'd be willing to post one to me if I send them the money. We can't order Festool from American commercial websites in Australia. Some protectionist nonsense I believe.

We can't buy Elixir strings here from anywhere in the States for the same reason. :evil:

Bob
Hi Bob,

I'll get you one. Make sure I know exactly which Festool sander your talking about (Actually only the ETS 125 is in the $165 price range - the rest are higher.) I have also seen 2 versions of that sander with different vacuum or dust collection bag attachments. And, I saw a 240v version of it (on Ebay), but it was from somewhere in England. If you can do the research to get one to Duluth MN 55811 as cheaply as possible, then I'll turn it around and get it to you. Mind you, it will be difficult not to try it out, but I'll resist. I'm guessing that the USPS will be the cheapest shipping to you, but we also have FedEx and UPS here, if you want to check those shipping options. Which ever way you go, I think the last leg will be by platypus.

Oh, same deal for the Elixirs.

PM when ready, and we'll work out the details.

Dennis
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Post by Hesh1956 » Mon Oct 29, 2007 2:15 am

Mike Doolin's original schedules for pore filling with epoxy (he used System III but this translates to any epoxy finishing resin) and then spraying with KTM 9 even though he tossed the KTM 9 were very helpful to me.

The biggest take-away that I got from Mike was that the surface should be "perfect" after you pore fill. The finish will only highlight imperfections, dips, what ever on the surface of the guitar.

So I completely agree with Allen and I am mindful to use grits like 220 before I even pore fill to really, really, level things. I also have some maple blocks that I sanded true on a surface plate to true up the sides when I am sanding them.

These days I am outsourcing my finishing since I grew a second head after spraying nitro in my bathroom 6 times...... My finisher, Tony Ferguson, tells me that my stuff is a pleasure to work on for the surface prep that I do. He says that he does not have to touch my guitars prior to pore filling that this in not the case for him very often.

Two guitars ago I dropped off a Koa OM and he asked me if I had seen this wood popped yet. I told him that I had not and he had a small cup of West Systems mixed up in a few seconds right in front of me and proceeded to pore fill the guitar while I was there.

I have the Festool ROS and it is the finest tool that I own next to the matching Festool dust extractor that you can plug the ROS into. In concert these two tools provide the best finishing sanding that I have seen and NO dust escapes the Festool dust extractor's HEPA filter. Highly recommended.

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graham mcdonald
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Post by graham mcdonald » Mon Oct 29, 2007 9:16 am

Hello Bob

I think it was the bloke who runs the company. They didn't really laugh, but did suggest that spraying the hard shellac did put it on too thick and that was the cause. The recomendation was that it be padded or brushed on. I didn't think it was on to thick and it did take a year or so until I noticed the crazing, very similar to the way nitro goes if it is too brittle. It might well have been a sudden climate shift which led to the crazing, or it might have been that I didn't allow enough time between coats. The idea of the hard shellac is great, a hard finish that doesn't need kidney rotting thinners, and I hope that your guitars survive the test of time.

I fully agree with Hesh that that the better you can get the surface before applying the finish coats the better. I have been using epoxy for pore filler for the past couple of years ( a finishing resen I got from a model plane shop) and one or two coats of that works really well under nitro, which I have gone back to after trying just about everyhting else!

I spray 6 double coats over two days, leave for a few days, then level with 180 or 240 grit and then another three double coats and leave for at least a week (if not two) before flattening with 400 wet if necessary and then 600 and 1200. If all the gaps get filled before the first leveling it works fine.

cheers

graham
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Post by Bob Connor » Mon Oct 29, 2007 9:51 am

Dennis Leahy wrote: Hi Bob,

I'll get you one. Make sure I know exactly which Festool sander your talking about
Thanks for the offer Dennis but sister Lillian is already on the case for me.

Really appreciate your offer though. Thanks.

Bob

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