In which I finally cut acceptable crown molding

A Ph.D. in physics is necessary but not sufficient to cut crown molding.  But I think I’ve got it.

 

The problem is not in computing the angles although that is important – the problem is in visualizing which way the cut has to go so that it will be right when you get it up on the wall.  To that end, I made a model inside corner and a model of an outside corner.  Now, I hold these pieces up to the molding on the saw to make sure I have the saw blade and the molding itself oriented the correct way.

 

Then there’s the matter of the angles.  I got tired of never understanding why the power miter saws of today have detents where they do so I set out to re-derive the math for how those angles determined. I failed.  But I did find the equations that somebody else had derived which was good enough for me.  I made them up into a spreadsheet so that I could enter any wall angle/spring angles combination and have it spit out the proper saw angles.  The most important thing I concluded from this is that a slight change in the wall angle can translate to a large change in the saw angle.  But how large is large?

 

I have always known in an academic sort of way that no two walls are ever square but I decided to actually measure mine.  I found that as I traverse the walls in my hallway, the angles vary from about 88 degrees to 90.5.  This doesn’t sound like much but when you hold out the bevel gauge and look at it, you can clearly see that it isn’t square.  The human eye is apparently very good at spotting tiny changes from the ideal.  We may not be much good at measuring absolute values of measurements but we are very good at spotting changes.  So…

 

These small changes in wall angle translate to some rather small changes at the saw; mostly because it’s possible to vary the spring angle of the molding pretty widely as you hold it up there and still have it look OK.  “Rolling” the molding in this way allows you to make the miters meet up.  This would be easy to spot on a wall that was perfectly flat all the way across but mine are not and there are noticeable hills and valleys along the length of the molding so I have the freedom to roll it one way or another and know that any gap introduced will pale in comparison to the gap due to wavy wallboard.  Caulk is inevitable in my house.

 

It’s difficult on my saw (which actually belongs to my brother-in-law since I sold mind) to make such small changes accurately so I just left the saw set at the detents.  (The bevel angle is especially difficult to set.)  When I get the molding up on the wall, there is usually a pretty severe gap at the top or bottom but I find that if I have the length accurately measured (as in within 1/16”) then the miters will go together if I “roll” (or twist) the pieces. 

 

So, the important lessons here is that I first of all, made models of each type of corner: all together, four pieces labeled “inside left”, etc to help me visualize what I need.  Second,  I have to measure the length very accurately.  Plus, I sometimes need to take a chisel and shave off a bump or overly round inside corner on the wallboard texturing to make things work out.  Finally, even though the exact angle is very important, after taking into account the waviness of my walls and ceilings, I can get away with just accepting the default saw detents. 

 

All I have to do is measure accurately and tack the molding up with a single nail in the center.  Then roll it at the ends until the miters match and nail it in.  After all that analysis, I come back to the age-old practice of measuring twice, cutting once, and using a little trick at the end.  Plus caulk.

Lube for Sharpening

And now, on the subject of lubricants when sharpening.  My background is experimental physics so I admit that I tend to overthink everything.

 

I emailed Christopher Schwarz once on this topic to ask him what he used as a lubricant while sharpening.  I had seen him on Roy Underhill’s show using olive oil but also had a video of his where he used water.  His response was that you can use anything.  I got a bottle of special honing oil from Dan’s Whetstones in Hot Springs because it came with a set of stones I bought there.

 

The honing oil smells exactly like 3-in-1 oil and, like 3-in-1, leaves that smell on your hands which I don’t like.  I also dislike the greasy feeling it leaves on your hands unless you wash them two or three times.

 

So I experimented.

 

I tried olive oil.  It works but the blades seemed to float along the stone more than when using a thinner oil.  I’m not sure if that’s a valid thought but it does indeed require you to wash your hands.

 

I experimented with water (not using my oilstones – which had already been pretty saturated with oil of various sorts; I did this on a diamond plate).  This is great and totally easy but I was left with a concern about rust.  My side-clamping honing jig froze up at the wheel until I spritzed it with WD-40 and then oiled it again.  Again, this works but requires a bit of procedure with oil to keep things free of rust so I figured why  not just use oil to begin with and save a step?  I’m much less likely to hone if I know there’s going to be a lot of procedure.

 

At that time, Schwarz mentioned online that he used “Camelia” oil which seems to me to be a bit hard to find.  And later on, in his “Supertune a Handplane” video  he mentions using Jojoba oil.  I remember back in the ‘70s when Jojoba started to be used in everything from hand lotions to shampoo.  I bit of research reveals that Jojoba is a natural product (like olive oil and many other oils) but which also mimics the natural skin oil to an amazing extent.  As a result, it tends to absorb into your skin and not leave them feeling greasy.  After honing, you’ll have metal swarf on your hands so you’ll have to wash but at least Jojoba should leave you not feeling greasy or smelly. 

 

I say “should” because I haven’t tried it.  It is available widely online but I haven’t been able to find any at my local pharmacy.  But in my shopping trip, I noticed that there are several “beauty” oils of a similar sort that advertise the same thing: natural oils that moisturize your skin without leaving you feeling greasy.  I noticed the generic (therefore cheap) version consists mostly of safflower oil with a couple of others thrown in; perhaps for looks only because they seem to be trace amounts.  Plus, a bit of scent.  I bought a bottle of this to try as a sharpening lubricant because it has little smell and feels less greasy.

 

In use at the stones, it works the same as 3-in-1 which was very good news.  Sharpness was achieved.  Furthermore, careful use of a paper towel got all the oil off the stones and blades without getting much if any on my hands so that I could just wipe off my hands and be done.  No smell, and no residual greasiness. So, I’m going with it.  If I run across a bottle of pure Jojoba, I’ll buy that and try it as well. 

 

Besides the greasy feeling, I also don’t like how any machine oil on your hands gets on the screen of my phone and/or my glasses.  I see plenty of people who clearly do not mind greasy fingerprints on their glasses or phone but it drives me crazy.  Perhaps because my job involves the use of lot of cameras and I cannot abide the out-of-focus condition caused by a dirty lens.

 

This may seem a bit odd to be obsessing over the topic of what oil to sharpen with but let’s face it; all the really sexy topics in woodworking like how to cut dovetails and sharpen saws have already been done to death.  This is at least something I can maybe contribute to.  Plus, if we can save ourselves a step and prevent ourselves from smelling like a lawnmower, then why not?  Then there’s this:

 

It’s a topic that’s too full of BS.  I mentioned the subject on woodtalkonline once and while most responses were polite, one guy responded that (and I’m summarizing) if you don’t use the exact right formulation that his grandfather used, you were going to ruin everything and anybody that says different (even Dan who has been producing whetstones for many decades) is WRONG.  This is just magical thinking.  And this is right after I quoted the guy that works AT THE WHETSTONE QUARRY who said that it did not matter – you can spit on the stones if you want and that works. I tend to go with evidence and if both The Schwarz and Roy Underhill say that, in their experience, you can sharpen with any liquid then I will tend to lean that way and try it out myself.  SCIENCE! 

 

My own experience (not rigorous scientific testing mind you) suggests that using something from the ‘beauty’ section of Walgreens can be not only effective but also cheaper and save you the step of having to seek out the rare Camellia oil, scrub your hands twice with detergent, and make your tools rust resistant all in one step. 

 

Incidentally, this subject comes up in the world of black powder shooting also.  In some rifles, you wrap the lead ball with a cotton patch in order to grip the rifling marks in the barrel and how you go about lubing that patch is a similarly religious subject.  Many products are sold which all claim to be the only thing to use and they all have their apostles.

 

There are those who do not mind smelling like a weed eater and that’s fine for you.  Keep on with it.  Do what works for you; the last thing I want to do is convince anybody to change their ways whether that be their sharpening regimen or their church.  But I hate sharpening and if I can save myself the cleanup step, then I’m going with it.

 

My next topic to tackle is the one of the oil can itself and why they all seem to leak.