This Week in Wood » Finishes

OMG – French Polish is amazing!

glennth — Fri, 09 Jul 2010 03:25:24 +0000

OK, I’ve spent the last week putting many coats of shellac on my guitar project. These have all been base coats. French Polishing the guitar is rather tedious but not very strenuous. Each coat is super thin so it takes a lot to get a good cover over the wood. After about 15 coats, the finish felt pretty smooth but had a lot of swirl marks (which looked like circular cracks in a class). I was a little worried about the final look at this point.

The next step is to apply a few final top coats. This is exactly the same technique with some minor differences. The first difference is that you level the previous coats using a high grit (I used 1200) sand paper with some soap and water (water for lubrication and soap to help the sand paper not get clogged). This took a bit of time but was also not very strenuous. The result had scratch marks that were nearly impossible to see but the cracks were gone. The next step was to rub in (in a circular pattern, hence the swirl marks) the shellac but this time with a few drops of paraffin oil. This oil allows you to rub out the swirl marks and get a glass like finish. After making sure there are no visible swirl marks, I then run the shellac pad with the grain making any marks nearly invisible.

I’ve done a few coats of this and the finish, while not perfect (hey, I’m still learning this), is absolutely amazing for any finish I’ve ever applied. With these kinds of results, I could get to like finishing my projects.

Now, I’ve got to do the same to the back and sides (I’ve done the top and neck). I will glue on the bridge first thing Saturday morning so I should be in good shape for my last guitar making class. This will allow me to come away with a working guitar. I’m very excited.

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OMG – French Polish is amazing!

French Polish, My midway point

glennth — Tue, 06 Jul 2010 04:50:01 +0000

OK, I’ve been progressing on my french polishing work. Each coat doesn’t take very long or really much work at all. The problem is it needs a zillion coats (ok, maybe closer to 12-18) and you have to wait a few hours between each coat. I’ve progressed up to 7 coats. My approach has me doing simple coats and then after about 14 coats, I do a little sanding. Follow the sanding with a few more coats with a little oil so that I can rub out swirl marks. I hope to be to the point of the last few coats with the oil on Thursday. This will allow me to glue the bridge on Saturday and be ready for my class on Sunday. I’ve been really pleased with the results so far.

The color of the sound board is not as even as I wanted but this is primarily due to my pore filling technique so hopefully this improves as I move through my guitars. Notice in the picture of the neck that I have a cover next to it. This cover is for the truss rod adjustment access. I am super pleased at the feel of the nec too. It is nice and smooth and feels much like the best guitars I’ve gotten to play.

Finish Update

glennth — Sun, 04 Jul 2010 03:51:57 +0000

I finished the epoxy pore filler. From a texture point of view, I believe I have accomplished the job. From a color point of view, I have an uneven tone. I need to explore pore filling more though I’m not sure I have the time to do it on this guitar. The neck and headstock are awesome while the sides and back are ok with the top being the uneven color.

I’ve mixed up 2 different shellac mixes. The first is platinum at a 1 lb cut and the second is amber also at a 1 lb cut. I’ve been reviewing techniques on french polishing and feel fairly confident that I can do this and get a good result.

I hope to begin the process tomorrow. I have to get quite a few coats down before Friday night. I want to glue the bridge Saturday morning. That should put me in good shape for my last Guitar class which happens a week from tomorrow.

Started the finishing process

glennth — Thu, 01 Jul 2010 03:26:01 +0000

My chosen finish is a shellac finish using a french polishing method.

I’ve sanded everything and started the first part of the process – pore filling. Pore filling is the process of filling spaces between the grain of the wood. It’s very important on the wider grained wood (usually the sides, back, and neck). I’ve read about 2 types of pore filling. One is using shellac mixed with pumice powder. I briefly thought about this and may try it on the next guitar (yes, I’ve decided there will be a next guitar) but instead chose the other method I read about. That method is using Epoxy to fill the grain. I’m not trying to get the wood covered with epoxy but rather just the spaces between the grain. I’m going to do a few coats though coats are probably a misnomer. After one coat, you sand the surface which should remove all but the epoxy in the pores. The reason for repeating seems to be to ensure an even/level surface that has all pores filled.

The big reason for this is that the woods used in guitar building are often open pored woods and the finish will often shrink into the pores. The result of this shrinkage is that the finish cracks (somewhat like orange peel finishes). In a guitar this would be a bad result.

My first coat of epoxy went on well so I’m hopeful that the sanding and additional coats will go on smoothly as well.

Guitar Building – A few small things

glennth — Wed, 30 Jun 2010 02:39:45 +0000

In getting the guitar ready for the finishing process, I also wanted to do a few small things.

First, the guitar’s heel on the neck was an area I wanted to modify. I’ve seen on some guitar’s that have interesting treatments on the headstock of the guitar that they do a similar/complimentary treatment on the heel of the neck. I had some left over burly wood which I used to great results on the headstock so this was a great opportunity.

Next, the guitar’s kit came with a black plastic cover for the truss rod adjustment nut access point. Again, since I had some left over burly wood, I figured this would tie into the headstock and make the access point nearly invisible. In the picture, I’ve shown both the black plastic and my newly made burly version.

Lastly, I’ve made sure that the bridge is ready (matching my tape job on the body for position).

Here is a quick shot of all the elements. I’m ready to start applying finish as soon as I receive something from Fed Ex (and no, they don’t ship everything overnight so I won’t get it till Monday I think!).

Shop Tour – Pictoral

glennth — Mon, 31 Aug 2009 21:44:11 +0000

I know, I know. Finally he shows his entire shop. Of course when you entire shop is less than 10′ x 16′ there isn’t much to show off.

First, here is my main work bench. Someday, I may build my own from scratch but I wanted to get to work so I bought a bench kit from Sjoberg. I did some research and for lesser expensive bench kits, it got lots of good reviews. There are better benches if you are willing to spend $1000′s of dollars (see Lie-Nielsen for example). A real big difference between many shop built benches (or these expensive ones I mentioned) and these in-expensive kits is the weight or mass. These inexpensive kits are prone to moving around as you use them. I’ve drilled holes into the leg bases and the floors so that I can have a removable anchor using dowels. It’s worked great.

Here is a shot of the entire corner where I have a quick/dirty shop made cabinet for hand planes/chisels/marking/measuring tools along with hand saws on the wall. I keep my saw benches (modeled after Christopher Schwarz’ design). This area has really worked out well as I move more towards using various hand tools. You will notice that I have a dust collection set up. This is somewhat the remnants from when I had my table saw (can you imagine a table saw taking up nearly the entire shop) but it’s still useful for shop cleanup and some of the remaining power tools (planer, sander). Notice that I still am working on that handcut dovetail hope chest.

Oposite my main bench is a secondary bench that I use for metal work (though I don’t do this much) and I can put a anvil or metal vise into the bench vises. Above this secondary bench, I have a cabinet purchased from the local borg which holds a few reference books and most of my finishing supplies. Also in the farthest corner, I have a scrap bin and trash on wheels (it’s helpful in such a small shop to allow everything to be mobile.

On the same wall but at the other end as the secondary bench, is where I have my benchtop drill press, benchtop planer, bench top oscillating sander, dovetail jig (for router cut dovetails). Above all that I have storage for fasteners and other misc hardware and supplies. Lastly, is my Craftsman (as in Sears) toolbox for hammers, screw drivers, wrenches, plyers, socket sets and such. Notice in front of the second door to my shop (which is hardly ever used) is a ladder. I use it to get to the overhead storage where I keep other wood odds and ends. Also you can just see my collection of bessy clamps that are vital to building anything.

Opposite the above power tool area is my Festool bench. It’s the orginal MFT 1080 (I think that is it’s number) bench (latest version is the MFT-3 which is a different shape but has the same essential features). I have the MFT bench on top of a shop made cabinet which holds routers (I have 4), circular saws (I have 3), router bits (never have enough), and some other misc tools. Next to that, you can see a band saw which I would like to change out the blade for a wider blade and tune it up so I can use it for cutting both smaller items (that the Festool circular saw has difficulty with) and cutting thicker material to be used for project. Behind the bandsaw, I have scraps that I haven’t put away but behind that I have a panel clamp system.

There are some other elements of my shop that are not actually in my shop. I have had several posts regarding my Sharpening Center which I keep in my garage. Now that you’ve seen the shop you can understand why. Also, if you noticed the dust collection looks like it comes through the wall, it does. I have a small shed outside of the shop where the dust collection system stays and makes it’s dust and noise which is not in the shop. Lastly, I have a sheet goods storage area in another shed (it’s a partitioned part of my gardening shed).

This is what makes up my woodworking efforts. I hope that you enjoyed the quick tour. I hope to put together a video tour as well but that will be later. If you have any questions, please post them in the comments and I will address them as I can.

How to determine how much finish is needed?

glennth — Wed, 19 Aug 2009 17:10:47 +0000

I’m working on finishing the Handcut Dovetail Hope Chest that I discussed several posts ago. In class, we used Shellac to finish the interior (ok, pre-finish). I’ve not used Shellac really. It seems like a really interesting finish and can provide some color to the work without the over powering nature of some dyes and stains.

Shellac is a finish that you try and mix what you need for the project as it has a more limited shelf life than some other finishes. My current issue, is how do you determine how much finish to mix up to have minimal waste (always have to mix a bit more than you need because it would be bad to not have enough)?

For me, it’s a guessing game as I don’t have any experience to tell me what to do. If there are any readers with experience with Shellac and can give me some insight, I’d love to hear about it.