Thursday, December 17, 2015

Final Project Process Blog

This blog post reviews the creation of this coffee table designed for THTR 1320's final project. It is one of two final projects that incorporates steel and welding. Of the two, I am the only one with no real background in welding. In this first welding project, the welds that I ended up making required the heavy cleanup afterwards.

The process, indicated in the linked proposal, went as expected. However, initially, I planned to use a hardwood veneer for the surface of the project. However, also mentioned in the project proposal, that this top would be replaced at a later time. The process of veneering surfaces was not covered in class and seemed like work that would later be scrapped anyway. To replace the veneered surface that would go over the B/C plywood, I decided that a few coats of black spray primer on both sides and a high gloss black spray paint would suffice.

On the first day of building, I worked to prep the salvaged 2' x 4' x 3/4" plywood. I started with edge banding the sides with pine iron on edge banding. The excess was trimmed using a flush trim tool for the ends and a special tool that ran along the long sides. This is where I began the first inspection of my work and immediately noticed some issues. First, the edge banding was not perfectly aligned to the sides of the plywood because both bow in the plywood and because the grain of the edge banding ran at a sight diagonal angle along its length. This caused the banding to tear out in periodically along  the run. This was of little concern since the edge banding would not be seen but was only there so that the end grain of the plywood didn't absorb all of the primer and paint.

Of greater concern was that where the edge banding met the wood, I had failed to notice that the plywood had torn out so that when the banding was glued on, one could clearly see small divots where empty space met the banding. To compensate, I peeled the banding away and cut a fresh, clean edge on all four sides. Then, I repeated the process of edge banding so that the table top was acceptable.

The C side of the plywood had two large of the laminated C face had torn away. I used some wood filler from Walmart to fill those voids before sanding them smooth. I also used the orbital sander to on the rest of the C face and the B face in preparation for painting.

Using the air compressor, I removed the wood particles from both faces and set the board outside against spare wall that already had paint on it and started with adding layers of black primer. I added four coats of black primer on both faces and the sides. I added three coats of the black high gloss paint. In the up coming days, I will add a few coats of spray polyurethane to seal the top.

During the down time between coats of paint, I cut the pieces and welded the frame. I found that the right angle clamps were very useful in holding the pieces together as I welded them. When I made the top and bottom assemblies, they were identical but when I welded the pieces that held them upright, I didn't remove the rather heavy clamps and just welded them in air. This lead to a bit of flex that I would have to correct when I cut and welded the braces. The welds were ground flat, and the frame sprayed with polyurethane. Finally, the top was sprayed and the table assembled.

Project Assembly:

Top cut and rabbeted.

Frame Assembly Pieces Cut

Frame Assembly Welded With Strapping

Project if I hadn't compromised with Newton

Completed Frame






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