Tag Archives: composites

Keeping Clean

I had a heck of a time coming up with todays post, life, the universe, and everything conspired against this post coming out at all today.

Todays topic is keeping a work site clean. Today I had the pleasure of cutting into some decking, a 40+ year old walkway that was originally cement over wood. Sadly the steel railing’s base was installed under the cement. Being a light weight cement it compressed and was ground out by the railing post which necessitated a repair.

At the time the repairs were made a section of the cement was cut back significantly and the void was filled with a hard composite, then the whole surface was covered with a coat of matte fiberglass and polyester resin. Since the repair was made, I’m guessing 20+ years ago, the cement has continued to deteriorate due to compression and moisture passing under the composite. The steel railing of course has some serious rust issues.

My task was to remove the rusted areas of the railing foot and weld on a replacement and button that puppy up. I cut into the composite/cement mess with a 4.5″ mineral wheel on my die grinder. The tool works fine for the job,but oy, what a mess of rubble and dust. This is where the clean work site comes in, with so much dust and chipped debris piling up I ended up developing a close relationship with my new 4 gallon Shop-Vac wet/dry vacuum. The area I was working on is only 12″ x 24″ but chipped cement and composits can make a huge mess.

To make clean up a simple affair I would chip out a 4 to 6 square inch area and then clean up repeating the process over and over. I would spend a minute or two each time I cleaned and then get back to chipping the old materials away. I was able to clear the space in relatively short order and at the end, I spent only 5 minutes of actual cleaning. More importantly, my work space though in a public area, did not inconvenience anyone. The dust was kept down buy the frequent stops to tidy the area and the chances of flying debris from kick-back were nearly eliminated. Another safety benefit was the constant removal of rusty materials that presented an additional health and safety hazard.

The point here is that keeping the work space clean and clear of debris is a mater of safety as well making it a lot easier wrap up when you are done.

Thats the end of my High School shop class lecture.

Till next time,


Got out this morning and did another material sourcing run. It didn’t go as well as I had hopped, but that’s okay. I have made some solid decisions on materials and can now start buying what I need for the 1:4 scale project, as well as buying materials for the full scale airplane. Full steam ahead!

Full Scale

First and foremost, I’ve been able to source a majority of wood products locally. However, it looks as though I will have to run with one of the regular aviation suppliers for the 1/16″ plywood. I can find 1/4″ and 1/8″ but that’s as thin as local suppliers carry. 1/4″ AA marine is relatively easy to find, 1/8″ is tougher, 1/16″ is nearly impossible in any grade.

I found a local source for aircraft cables of the mechanical control variety; not electrical, which I suppose would be obvious to anyone who has been reading this blog since I don’t plan on installing an electrical system in the airplane. It looks like Orchard Supply carries aircraft cable as a regular item.

A local supplier for composite materials is TAP Plastics. I had a feeling it wouldn’t be particularly difficult getting some of the composite supplies locally. They don’t have all of the right fabrics, but they do have some. I am not sure about the resin and epoxy they stock, but for the basic materials to work with them, well those they have in spades. I will check out the chemical stuff later when I get to a point that I actually need to think about composites.

1:4 scale

I am rapidly coming to the conclusion that I will need to manufacture the ply products I need. The lumber is readily available, ply products on the other hand… With the full scale ply sizes being 1/4″, 1/8″, and 1/16″ the 1:4 sizes are 1/16″, 1/32″, and 1/64″ respectively. As I said earlier in this post, it is tough if not impossible to find ply this thin anywhere locally. So, I have resigned myself to the arduous task of manufacturing a replacement material.

At this point I think it will be a laminated paper product. Layers of a a heavy water-color paper should do nicely, maybe a 25 sheet pad. With any luck the end product will be moderately stiff ply-board in the appropriate thicknesses. In 1:4 scale a 4’x8′ sheet of plywood is only 1’x2′ so it shouldn’t be difficult to find the paper stock large enough. I was thinking of using Gorilla Glue as the laminating adhesive mainly because it is very strong and you can use water to thin it for spreading a very thin layer evenly across the surfaces of the laminates. I was hoping to avoid this but ya gotta do, what ya gotta do.


In truth the only composite parts that I would need to build are the engine cowling and the turtle-deck faring which isn’t even a required part, though, I must admit, I am definitely warming up to the idea.

The EAA Chapter 62 meeting I mentioned in the last post got me thinking about composite materials and processes. I haven’t done any fiberglass work in a long time but that is going to change with a day-job project that I recently started. It has some fiberglass work that needs to be done, so I figured I could brush up on those skills and maybe put some of the new techniques into action.

I purchased a book on fiberglass repair and construction to refresh the old gray matter on the subject. It has nothing to do with aviation but it is all about the basic skills for fabrication and repair in the medium. The book was published in 1988 so some things might be a little different or out of date material-wise, but the skills should transfer reasonably well.

Till next time, blue skies and tail winds,