Archive for October, 2012

Building the sand blast cabinet

Once the hopper was done (I can’t say that without thinking of the Dish Network commercial) I moved on to building the sand blast cabinet.

The cabinet will measure 5′ wide x 6′ high x 30″ deep. Back in February I picked up 16ga sheet that I cut out the panels from. I struggled with how I was going to build the cabinet until I came across the idea of building some scaffolding. It’s not an original idea, it’s just how I chose to put it together.

It started with building a wooden framework that I could clamp the 16ga panels to. In this photo I’ve placed the door frames against the scaffolding to make sure I had the dimensions correct.

Then I began to hang the sheets of metal. There are the rear panel, top, window, front panel, two side panels and two legs. Here’s a picture showing everything but the side panels and the legs tacked together.

I created another framework to support the hopper while I moved it into position inside the cabinet.

Next step was to build the legs. If I was to do this all over again I would make the legs and the front panel from a single piece and cut out the front opening. It started with laying out the 16ga sheet, using a straight edge and the plasma cutter and cutting out a piece.

Then once I have a piece that is the correct overall dimensions, I need to reduce it down by cutting the angle for the legs. The legs are about 2′ tall with a taper from 20″ at the top to around 8″ at the floor. This is around a 60 degree angle. So using a straight edge and the plasma cutter

I end up with this shape

and using a set of butt joint clamps, I can clamp it to the rest of the cabinet.

The side panels were cut out and drilled that I’ll use to weld the leg panels to the inside of the door frame.

In this picture I’ve clamped the side panels to the door frame prior to welding.

Here’s it’s all roughly welded together before inserting the hopper.

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Sand blast cabinet – hopper

I didn’t get any pictures, or if I did, I can’t find them, but after building the work support out of 1.5″ x 1.5″ x 11ga angle iron that measures 58″ x 34″  this will give me plenty of space to clean a fender and possibly a bumper.

I started with cutting out the hopper out of 18ga sheet which I then clamped to the work support frame.

I was going to use a spring loaded trap door at the bottom of the hopper to allow me to drain it and replace the media when necessary. The trap door I’m using came from TP Tools, so I made a spacer out of some steel I had laying around and clamped it in the hopper. 

I kept cutting out the 18ga sheet to make the other two sides and ended up with a decent funnel shape. When I was in high school I worked at a HVAC company where I made plenums. I sure wish I had the sheet metal brake and spot welder that I used in that shop. I then proceeded to tack weld it together.

After everything was together I moved on to fully welding the joint and grinding it smooth.

I double-checked that the trap door would fit the hopper.

When this was done, I turned it over and added seam filler to the joints. The idea is to make a box that is air tight enough that the vacuum will draw air through the inlet and not all over the place. I don’t want it leaking like a sieve. It’s not a good picture but it’s all I have from this step.


Long lost summer

It’s been a long time I last updated.

When I last posted I was lining up where the front cross-member and the brackets for the 1985 Corvette suspension. On the chassis table I need to build what I’m calling “stations”. These are locations along the length of the frame where specific attachments would be bolted to the frame. These attachments are things like the front & rear bumpers, running board brackets. These stations help locate the frame on the chassis table and keep everything lined up, in addition to building additional stations to help locate the front cross member and the brackets to mount the independent rear suspension of the ’85 Corvette.

I was working on building the stations for the front and rear running board brackets. The flat bar has this hard layer to keep the steel from rusting. It’s a pain to remove and even with 40 grid flapper disk, it takes a lot of effort to remove. I also noticed that the suspension brackets were developing some surface rust. I wanted a sand blast cabinet.

I went online to TP Tools and really liked their cabinets, but after starting with the basic model and upgrading to the next one “because it’s only a few hundred more”, when I was done I was looking at a $3500 cabinet. Years ago my dad built one out of 18ga but I gave it to my dad’s lifelong friend when he passed away. Because I’m my fathers’ son, I decided that I’d build my own.

Off to Discount Steel to pick up some 16ga for the main body, 18ga for the hopper, 11ga for the doors and 1.5″ x 1.5″ x 11ga angle iron to build the work support framework.

I started off with trying to build the hopper with the 18ga sheet. It was easy enough to cut out with the nibbler but then I tried to bend it. I thought I could just clamp it and bend it over. This didn’t work, so then out came the body hammer and I tried to bend a 1″ flap over 24″. This turned into an absolute mess. I just wasn’t happy with the results.

After looking online for a sheet metal brake that could bend 16ga sheet over 5′ long I came up with the brain-dead idea that I could build my own sheet metal brake.

After screwing around with this idea for a month I was severely unmotivated and was stuck like this for several months. I didn’t get back to the shop until August.

Over the next few posts I’ll describe the progress I’ve made with the sand blast cabinet.