WSM Thermometer Mod

by zydecopaws on June 12, 2009

After all these years of using a candy thermometer stuck through a cork and jammed in the top vent of my venerable pre-2009 18.5 WSM, I took the plunge today and performed elective surgery to add a “built-in” addition to the lid.  But before we see how that is done, there must be a “before” picture.  Here’s what I used to do; note the clogging of 1/3 of the top vent and the inability to gain any form of top vent control (short of cramming in more corks):


Out of respect for this thermometer which has served me well for years, here is an up-close and personal look at it in all its charred glory.  Note: this is not the original cork; they got replaced about every fifth or sixth cook depending on the degree of deterioration.  The one in this picture only has about three cooks worth of experience…


Ok, out with the old and in with the new.  I went to the local Home Depot and picked up a cheap Char-Broil Universal Fit Temperature Gauge, which the label says is designed to replace temperature gauges on most gas grills.  It claims to be accurate (we’ll see) and came with mounting hardware (aka, a wing-nut).  Now you might be asking yourself why I didn’t get something more accurate with more temperature divisions.  I’m cheap, and sometimes impatient.  This thing cost less than $10; if it doesn’t work it gets tossed, I already have the hole drilled, and I chalk it up to lessons learned (and later write a post about the experience).  Win-win.  Did I mention impatient as well?  I’m spending the day at one of the regional parks and cooking for about 50 people that are attending my daughter’s year-end SCIOLY party.  Since the WSM is going with me to help reserve the shelter and tables (and cook pulled chicken), I thought it needed some dressing up for the occasion.  Anyway, enough story, on with the modification.  Here’s a picture of the new temperature gauge:


Not very big, not very impressive, but it should be good enough for my purposes.  Next step was to cover the drilling area with some blue painter’s tape.  This helps keep the chipping and cracking down as well as the drill bit from sliding around.


As you can see from the picture I chose to put the gauge in the lid.  I know JB said to not do this, but I’ve had good luck with lid thermometers in the past, and for another $10 I can always add another down near the grates (and may, at some point in the future).  Next step is to use a center-punch to create a small crater that the drill bit can sit in.


Not shown it the picture above is the hammer hitting my finger.  No pictures, didn’t happen.  Next step is to drill the hole.  I have a Unibit; if you don’t have one of these I highly recommend getting one.  They are a bit pricey, but great for drilling holes of increasing size in metal.  They don’t slip around a lot, and make the drilling process real simple.


Once the hole is drilled, remove the tape and inspect the damage.  In my case there is a bit of chipping in the porcelain finish, but once the thermometer is in place you not only don’t see it, but the chipped part was completely covered by the mounting bracket which should limit the exposure to moisture.


From there it was pretty simple to attach the gauge with the wing-nut.  Here’s a picture of the finished product:


Total modification time was about 10 minutes.  It took me longer to find my safety goggles (please wear them when drilling as even with the tape pieces of stuff goes flying everywhere) than it did to perform the surgery.  Now it’s time to load the WSM on the truck and head off to the park. I will be verifying the temperature independent of the gauge to see how accurate it really is, and report back later…

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