A Small but Sturdy Lab Cabinet
#7
I got an e-mail from a former colleague who wanted to know if I wanted to quote on a cabinet they needed to hold a new MTS universal test machine in the lab. The machine weighs about 500 lbs and he wanted the cabinet to be able to support at least twice that. Here is a sketch of the cabinet I designed with a general idea of the size of the MTS machine that will sit on it.



I got the job, with a two week deadline. I ran right up against the time limit because it took a week to ship the paint and hardware from MN, but I finished it earlier today and all is good.

The completed cabinet looks like this.



The top is Formica on two layers of plywood and is 32 x 40". Instead of using liquid contact cement and applying it with a roller like I have in the past, I tried a 3M spray adhesive I saw at HD.



It worked great. You can adjust the width of the spray, which actually comes out like a string and not an aerosol. You can set it more narrow to do the edges and then wider to do the top. I applied three coats spraying each at a different angle. Like typical contact cement the bond is instant when the two surfaces contact each other.

The overall height of the cabinet is about 20". The legs and top stretchers are approx. 3" x 2" hard maple. The lower stretchers are 2". The frame members are joined with 3" long, 1/2" loose tenons. The panels are 1/2" maple plywood and are glued into dados cut in the frame members. The cabinet sits on leveling feet, each capable of supporting 5000 lbs. Overkill, for sure, but they looked right to me.

The drawers are made with 1/2" Baltic birch plywood, including the bottoms, and are joined with 1/2" finger joints cut on the TS. I really like this approach because they are fast to make, are incredibly strong, and look good, at least to me.



The slides are 100 lb, 18" K&V side mounted, full extension, soft closing slides. I've used them several times now and like them a lot. Easy to install and smooth running. The drawer handles are stainless steel; no worries about corrosion or finish coming off in a couple of years.

I finished the drawers by first spraying them with Sealcoat shellac, and then top coated them with EnduroVar. I sprayed the cabinet with two coats of BIN shellac based primer. The finish was two coats of Enduro White Poly.



I sprayed all four products with my new Qualspray AM-6008/PPS spray gun I bought from Homestead Finishing. I posted a short review on it in the Finishing section a week or so ago. I bought the 3M PPS pressure cup version of the gun which allows you to spray at any angle, even upside down. That made spraying into the cabinet opening really easy as I could tip the gun horizontally when I needed to. You also don't have to worry about having too little finish in the cup because there is a flexible inner liner in the cup and the air pressure collapses the liner which keeps supplying finish to the gun until the last drop. The gun sprayed all the products great. Enduro White Poly has a viscosity of around 100 seconds through a #4 Ford cup which would be a real challenge with my gravity feed HVLP guns w/o thinning. But with the pressurized Qualspray gun I had no trouble spraying it with a 1.3 mm needle/nozzle. And that gave a beautiful finish, like it came from a factory.



The Enduro White Poly will run if you spray it just a little too heavily so I had to be on my toes to avoid that. Other than that, I liked it a lot. It covered well, dried pretty quickly, sanded easily between coats, and had the same color and satin sheen over the whole piece. I think it's going to be pretty hard and durable after it gets to full cure in another 5 or 6 days.

Thanks for looking.

John
Reply
#8
Looks better than if "it came from a factory." And it's exactly what they wanted, not the least of necessary evils.
Reply
#9
I like it!
I'm a bit surprised they let it in a lab setting, though.
At my work, they are adamant about reducing 'fire load' (i.e. anything wood).
Good judgement is the product of experience.
Experience is the product of poor judgement.
Reply
#10
Nice design and I really like the finish. Ken
Reply
#11
Must be a Canadian thing, Paul, thankfully. There is so much wood in those labs you could roast marshmallows for a week. And they are only 4 - 5 years old, too. Funny you mention that, though, because the lab where this will go, and the MTS machine that will sit on top of the cabinet, has all kinds of little heaters running as high as 1100 C. I designed and built most of them when I worked there. If you are sitting in front of the MTS those heaters are mounted at at about head height in the test machine, which makes them easy to work on and at the perfect viewing height.

Even in our early days we never had an accident, and the last generation I designed had several safeguards built into them. The guy who runs that lab now has added some very well thought out guards, mostly to protect visitors who just want to see how hot 1000 C is. We also installed a pretty well thought out fire suppression system, just in case, and a guard checks the room at least once an hour after business hours. In twenty-five years of doing high temp. testing, day in and day out, we never had a fire related incident. We did have a water cooling line burst once though that caused some water damage. And I did burn up a lab bench in another lab once with a heat gun! You know, I worked in and managed part of that lab for 32 years and we never had a lost time accident. We were all pretty proud of that.

John
Reply
#12
Beautiful work, John, as usual!

Doug
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)

Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.