FLW Cabinet - #13 Finishing the Top Glue-up & Sharpening a Scraper

The next day I glued the third board to the stack then set it aside so the glue could cure.  The second top is next and the process is the same as with the first.  Below you can see the three-board glue up in the background and the current two-board glue up in the front.

After letting the glue cure overnight, I added the third board to the second top and was ready to flatten the first top.  To hold it in place it is edge clamped in my workbench.  As a result of the careful glue-up there was not much to do.  The actual glue removal and nearly all the work is done with a card scraper.  That’s the rectangular tool in the center left of the photo.  I know it looks just like a flat piece of steel and that’s because it is.  What makes it work is a tiny little razor-sharp burr on the edge.  With that burr I can take off paper thin shavings cleaning up the surface in just a few minutes. 

When I am done with the scraper some sanding is done so the surface matches the rest of the pieces.  Last is to trim the long edges so they are parallel then crosscut the ends to even them and make them square with the long edges.  The next day the clamps come off the second top then I go through the same flattening, sanding and squaring process as with the first top.

In other projects I have talked about using a scraper and how useful it is.  What I don’t ever remember is showing how to put a burr on a scraper.  That’s the catch as without that sharp burr it does not make the thin shavings, it just makes sawdust.   With that in mind here is the process I use to get the burr.

The initial step is to create a square corner between the face and the edge of the scraper like in the top example.  Depending on if it is a new scraper or one that just needs a lot of help to get a new burr you could have something that looks like the bottom image.  Neither of its right edges are square.

In either case you need to flatten the faces.  To do this I put the scraper face down on a flat granite slab then grab some 220-grit wet/dry sandpaper and a spray bottle with water in it.  Using a flat block, I apply firm pressure then sand back and forth until a band at the edge of the face is flat. 

You can tell when your done as you will get an even scratch pattern where you have been sanding.  When you get there move to a finer grit paper like 400 and repeat the process.  Going finer to 600 or 800 grit will just improve the quality of the burr.  If you are recreating a burr you only have to use the fine paper as a touchup.  In this case I was starting with a new scraper.  Here is what that looks like when it’s done.

Next is to work on the edge.  I clamp a fine file to the workbench then use a block of wood and spacer to hold the card square to the file. 

With that setup run the scraper back and forth along the file until when you look at the edge it is flat with a smooth surface.  In truth if you get out a magnifying glass the edge will look anything but smooth.  Here is what I mean.   Now it may look a really rough in the photo but remember the scraper is just over 2 hundredths of an inch thick so it’s relatively thin in real life.

To get a smoother edge replace the file with 220 grip paper, sand then replace with 400-grit paper and sand.  After that lightly hone the faces with the 400-grit paper to get rid of any little bits of steel that may have been created while you were working on the edge.  If it’s done right when you run your finger nail 90 degrees to the face/edge corner you won’t feel any raised lip.  Remember to check by using your finger nail at 90 degrees to the edge because if you run the fleshy part of your finger parallel to the edge you could very well need a bandage.

With a good 90-degree edge between the face and the edge it’s time to create the burr.  The burr is made by using a hardened steel rod or burnisher.  Here is what mine looks like.

Now it’s time to form the burr by rolling a little bit of the steel out so it points toward the face.  First step is to hold the burnisher square to the scraper and sweep it across the edge pushing a burr towards the face.  Second step is to hold the scraper at a just a little bit of an angle like this and sweep it across the edge pushing the burr down and towards the face.

I like to put the scraper in a vise and hold the burnisher in both hands so I have better control over both the burnisher angle and sweep.  Once again it does not take a lot of pressure maybe 10 pounds to roll the burr.  You are not trying to crush it but roll it over.  To little is better than too much. 

When done you probably can’t see the burr but you should be able to feel it.  To give you an idea of the size the photo below shows the burr as a very thin bright line right at the edge.  The penny provides some scale.  If when you test the scraper it’s not working try holding it at a different angle.  If that does not work make a couple more light passes with the burnisher on the edge.

Eventually the scraper will get dull and just make sawdust, not like these thin wispy shavings.  When that happens it’s time to go back and use the 400-grit sandpaper on the face and edge to get rid of the burr and create the 90-degree corner.  Pull the burr as before and you are ready to go.  After doing this a number of times the steel right at the edge will get work hardened and you will need to use the file to get rid of the brittle hardened steel there.  You don’t have to take off a lot of material, just filing it down until you can see the file marks on the entire edge is enough.  Don’t be discouraged if you can’t get it right away.  Between squaring the edge and pulling then rolling the burr there are a lot of places where it can go wrong.  Take your time, use a light touch with the burnisher and it will come.  It’s all worth the effort to get it right.

Since the title of this blog is Dave’s Projects & Things the following certainly falls into the “Things” category.  Here in New Mexico in mid-August the chile peppers ripen and become available for roasting.  It’s a regional thing where every grocery store sells them in bulk and includes the roasting.  Late last week I bought a 25-pound box of hot long green chiles and had them roasted.  The commercial roasters have an open grate rotating drum with a series of huge burners at the back that in just a few minutes blisters the chiles skin and cooks them.  Here is what a typical unit looks like with a 25-pound load.

When the roasting is completed the chiles are dumped into a big plastic bag put back in the box and they are ready to take home.  An interesting byproduct of them setting in the trunk on the way home is for a couple of weeks the car smells like roasted chiles.  After roasting they need to steam for at least 15 minutes before bagging and freezing.  What you ask do I put them on?  Well, I have been accused of putting them on everything which is almost true but they are great on about anything off the grill plus in stews, pasta and rice dishes.  Really, just about anything that where some spicy smoky heat is needed including pizza.  Here are the 25 pounds bagged, frozen and ready to use which will last me right at a year.

Next up – Faux Tenons, Side Spacers & the Back