Epoxy Report

Hudco's Clearstream 9000 laminating resin

Now that I’ve done scores of layups and can proclaim myself an expert at room temperature wet layups, I can say that I’ve been very pleased with the performance of Hudco’s Clearstream laminating resins.  I received two different hardeners with my initial shipment, a slow and a fast, as you’d expect.  Since temperatures in the Seattle area are below the national average I received more of the fast hardener, per Stan Montgomery’s input.  Typically I can get about 45 minutes of working time out of a fast batch.

This resin is low odor, easy to work with, and cures at relatively low temperature.  I haven’t tried many of the other epoxy resins popular with kit builders, so I can’t site any direct comparisons, but if I were to buy more epoxy, I would certainly seek out more of this stuff.

A friend of mine used to work for a large adhesives company – one that supplied Boeing with adhesives and laminating resins – so I got some of his samples from time to time.  I did a side by side comparison of his laminating resin that met Boeing specifications, and I found the Clearstream to be better for the amature builder: odor was lower, easier curing, and slightly better peel strength in my unofficial bench test.

I did call Hudco to order some more epoxy at one point, but was shocked at the price (nearing $200/gallon as I recall) which is much higher than a gallon of say West Systems.  Stan Montgomery ended up sending me some directly without charge, which was a nice gesture.

I’m not sure how Glassic Composites selected Hudco as their epoxy supplier, but I suspect Stan had some connections with the company.

Last time I checked their website, I could find no evidence of their Clearstream 9000 laminating resins.  Perhaps they discontinued the line.

Building in the Winter

I had to quit working in October, about 120 hours into the project, when it became too cold for epoxy work. I should have planned ahead back when I was in the “preparing the workshop” phase, but I completed the workbench just days before the kit arrived, and by then my mind was on the airplane–not on heaters.

Nevertheless, mother nature caught up with me, the ambient temperature continued to decline, and I could procrastinate no longer.

I considered many heating options for the garage and my first solution was to purchase a 4000 watt, 240V electric heater from McMaster-Carr. According to their chart, 4000W should have been plenty to heat the volume of my garage. I ordered it. It arrived. I plugged it in to the outlet that I had wired especially for my compressor, and off it went. But to my disappointment it made more noise than heat (the fan wasn’t balanced very well). Clearly, it wasn’t going to keep my garage in the mid 70’s throughout winter, so I sent it back.

I considered tapping into my house furnace and running a duct to the garage, but that presented a problem with the thermostat (being located in my living room) not to mention the hassle of running additional ducting and cutting through walls, etc. There were plenty of propane heaters on the market that would suit my needs, but I dreaded the repetitive task of refilling propane tanks. Finally I settled on a natural gas convection heater, which I also purchased from McMaster-Carr. This heater had a 60,000 BTU/hour output and would be much more convenient since I had a gas line running nearby. So I ordered it, and while awaiting its arrival I ran a gas line into the garage. I chose a convection heater because I wanted to heat the entire volume of air in which I was working, as opposed to a radiant heater which primarily heats objects in it’s path. Convection heat is much more even, and better suited for composite work.

My garage is insulated so heat loss was not a huge concern, but just to boost efficiency I insulated the garage door too.

The natural gas heater works great, and burns very clean, but since it’s unvented and I really didn’t want to kill myself, I bought a carbon monoxide detector to monitor any build up of that stealthy, toxic gas. It has a digital readout so that I can see the actual PPM concentration of CO in the air, which is pretty neat. Happily, CO levels are well within the acceptable range when running the heater.

Finally, for local heating, I purchased a small electric space heater (1500W max). It was inexpensive ($25 at Home Depot) and works great for curing things inside the fuselage. I just set it inside, plug it in, seal up the aft fuselage opening, and it keeps things nice and warm in there. Then I can shut down the gas heater when I’m done working for the evening and let the local cure continue.

Preparing the Workshop

My garage before the "workshop" conversion.

Having recently moved into my townhome, the garage was fairly empty to begin with, so I didn’t have to store, sell, or otherwise throw out a bunch of stuff, which was nice. It was also sheet-rocked and insulated which saved even more time. The below photo is my before shot (click on the photo for a larger image). I’ve managed to misplace my after shots, but when they turn up I’ll be sure to upload them.

The first thing I did was to remove all the miscellaneous shelving that the previous owner had installed and patch up all the holes in the sheet rock. Then I primed and painted the walls and ceiling white, which took way longer than I imagined. Good thing I didn’t choose painting as a career. Next I installed (4) 4 foot fluorescent light fixtures on the ceiling so that I’d have plenty of light. There were two incandescent light fixtures in the ceiling already, so I didn’t have to do any electrical work other than swapping the fixtures for power outlets.

I wasn’t going to get off scott-free (what does that mean, anyway?) with all electrical work, however. I planned on purchasing an air compressor, and most of the larger ones I looked at ran on 240 volts AC, and my garage didn’t have a 240V outlet. I discovered that there was 240V wiring running over to my dryer, but since the dryer was gas, it was not energized. All I needed was to install a 20 amp circuit breaker in my panel, splice into this wiring, run it out to the garage, and install a NEMA 6-20 outlet. Once again, this took longer than expected, but the finished product looks pretty professional in my opinion.

What workshop would be complete without a good work bench? I thought about this for a long time, and went to Home Depot a bunch of times trying to figure the best work surface that didn’t cost a fortune. One day I was talking to a coworker about this, and he mentioned that his neighbor had some bowling alley lanes, cut up, in his yard. Sounded like a good future work bench to me, so he managed to cut off a 44″ by 8′ section for me. I had a friend with a truck help me move it… good thing, as it weighs a ton (not literally). Another friend helped me build a support frame out of 4x4s, then lift, mount, and fasten the surface to the frame. It all worked out great, and the total cost was only about $50.

In between all these projects, I was buying tools. Below is the minimum required tool list from the SQ2000 construction manual. I have obtained nearly all of these tools at this point, as well as a 6.5 HP Craftsman air compressor and a host of pneumatic tools. The compressor is a great asset, and I would encourage any would-be builders to make the investment. Regardless of the ability to run pneumatic tools, just having the air gun is a great asset for removing dust and such. The only drawback is noise–not that it bothers me, but since I live in a townhouse I worry about disturbing my neighbors.

It was June, 1998 now, and the workshop was basically complete. I bought another free-standing storage unit and put up some more shelves, including one over the work bench with a rod to hold one roll of fiberglass. I considered building an enclosure to hold several rolls of fiberglass, but decided it would be better to keep the idle rolls inside the house. I only use one weave at a time during layups (generally) and keeping the other rolls in the house will keep them dust- and moisture-free.

Soon the kit would arrive and I could focus my efforts on building a plane, instead of building a workshop…

[table id=6 /]