Got the basement workbench cleared off enough to move rib production indoors. So far I’m only using one jig, but I’ve knocked out two ribs now. I need to get the second jig set up. One rib per day isn’t going to cut it. Sure is nice working in the basement instead of the garage though.
It’s damn cold outside!
I’ve been wanting to get back to building ribs. The garage bench has been piled too deep to get anything done, and now it’s been below zero for over a week solid. Insulation or no, it’s damned cold out in the garage. Too cold for epoxy to cure, and too cold to work.
So… there’s a perfectly good work bench down in the basement. 8′ long and rock solid, built by Dad back in the 1960s. It’s been pretty much completely covered up for the past several years with a collection of parts, partially-disassembled or -assembled prototype projects and assorted debris from the side business I was running, plus a CNC router that took up about 3′ of it. I have cleared most of it off (much of it into a trash can). The CNC machine is shelved for now; I’ll maybe resurrect it when needed at a later date. It will probably come in handy for cutting the instrument panel and/or nose ribs.
The next issue is containers for the geodetic rib braces. There are 24 braces used in each rib, all of which are of course slightly different. Just enough so that none are interchangeable. I was using paper cups to hold them in the garage, but it’s a completely unsatisfactory solution. In the basement I think I’m going to try stapling taller plastic cups along the back edge of the bench and see how that works.
I’m not moving power tools down there from the garage, so new geodetics will be cut with a razor saw. We’ll see how that works out… it’s one of those jobs I wish I could set up a machine or fixture to do. It’s 24 different lengths with over 40 different angle cuts, so I’m not sure how I’d make that work. Even cutting them out in batches on the band saw meant fine-tuning each one with a sanding block before assembly. It’s fiddly work and tedious as hell. Classic gusseted ribs would be a whole lot faster and easier to build. If I were starting this over I’d probably just depart from the plans and build them all that way; I’d probably have them all done by now.
Getting ready for winter…
It’s only late August, but I’m trying to get started on cleaning up the garage / workshop for the winter. I can’t build in its current state. Too many other projects, too much clutter. I’ve got to get stuff put away, thrown away, stowed, etc. Then I want to get the rest of the geodetic strips shaved down for assembly, so I’m not out there all winter miserable as I run them through the sander.
Mixing epoxy
I’ve been mixing epoxy in the little plastic medicine cups using “craft sticks” (think Popsicle stick). I thought I was doing a pretty good job of stirring, spending some time scraping the sides and swiping along the bottom corners of the cup to ensure everything was mixed up.
Last night I mixed up about 2 cc of epoxy, mostly just to try out my new syringe dispensers. I let it sit in the cup with the stick propped up in the center. Today I popped the slug of glue out of the cup. Lo and behold, there are sticky spots around the edge! Nearly all of the glue is perfectly hard and cured, but there is just a tiny little bit of uncured epoxy right around the bottom edge. Apparently the stir stick is not a good tool for making sure ALL of the material gets mixed together.
In light of that discovery, today I did another 2 cc sample. This time I did the mixing with an acid brush with the bristles trimmed down to about 1/4″ to 3/8″. After mixing I cleaned the brush out with a little MEK, just to see if that would be worth doing or not. We’ll see how that one turns out after the epoxy has had a chance to cure. Acid brushes are pretty cheap, so even if the MEK cleanup doesn’t work out it’s not a big deal. You can buy the brushes by the gross for around $0.12 to $0.15 each. But what will I do with about 950 craft sticks? Good thing I have grandkids.
Prep work
I’ve been away from building for a while dealing with a remodeling project, the annual condition inspection on the RV-12, Oshkosh and few other odds & ends. At Oshkosh I discovered that the wood shop guys had actually saved my miniature wing rib from last year (2016). I brought it home with me, of course. Last night I pulled the staples, cleaned it up and sanded it, and gave it a coat of clear polyurethane. I figure it will make a nice wall decoration for my office.
Last night I also started cleaning up some of the enormous mess in the garage so I can get back to building. I’m not quite there yet, but tools are slowly making their way back into drawers and onto pegs. It may take a few more days, but it will be nice to get back out to a garage that’s not a complete disaster. There are 14 wing ribs hanging on the wall, and the guy on the Biplane Forum is catching up with 11 finished. He can work faster, since he can pull his ribs out of the jigs as soon as they are stapled. I need to step up my game!
I did pick up a good idea from that discussion — using cut down acid brushes to mix & apply the epoxy. They’re cheap, and it looks like I might be able to get more precise application of the glue where it’s needed, in the amount needed, with good penetration into the wood grain. I’m anxious to try that, I have a handful of brushes here. And, I got some of the epoxy into 60 cc syringes so I can dispense exactly the same amount of each component. I know it’s not terribly critical with T-88, but I still want to be as accurate as I can.
Fixing up the steamer
I built two more ribs last night and took them out this morning; I’m up to 14 now. I’m trying to 3D print some clamps too use on one of the jigs that has locating blocks too thick to use the small red sprig clamps I bought. of course first I have to fix the 3D printer…
When I used the steam box, the door warped — no, curled outward. I flattened it out, but because everything isn’t perfectly square it really only fits on one way so I can’t just flip it over. Tonight I cut a couple of 3/4″ square stiffeners and epoxied them to the outside of the door. I need to bend some more pieces of capstrip, and I can’t do that until the door is usable. We’ll see if this is enough or not, should be interesting at least.
Built a steam box
Last night I built a steam box out of 1×6 boards. All that remains to be done is to put some foam weatherstrip on the door and run a few dowels through it to get the wood off of the bottom of the box for steam circulation. The steam generator arrived a few days ago, so once I get the box finished up it will be ready to go. I found that the Wagner steamer hose will mate with 1/4″ pipe fittings. I spent a little extra for brass rather than galvanized iron. I also re-worked my bending form with a gentler curve, providing a fairly close match for the rib shape. It won’t give me a perfect fit, but will get the capstrip close to the curvature needed.
Shaving the geodetic pieces
Yesterday I tackled the problem of the rib geodetic pieces. The thinnest I could order from anywhere was 1/8″, and the plans call for 3/32″ thick. What I got from ACS was actually a bit oversized at .130 to .140. So, I need to shave about .040 to ..045 or so off of 120 or so 6′ long strips of spruce.
I tried a small razor plane… no joy there. Maybe it was my technique, but the blade dug in and left a very rough, uneven surface. It’s quite possible I could make this work with a “real” hand plane, but I’d have to go buy one, then learn to use it properly, and let’s be honest — right now I’m a little impatient to start building. I tried spinning up an end mill in the CNC machine, but it was obviously over-taxed and would take several passes. Probably the wrong tool for the job. Maybe a router bit would have been better, but there was also a work space issue, and the small motor and flex shaft drive was not going to be up to the task. I knew I was fighting a losing battle there. My Harbor Freight belt/disk sander seemed promising, but the top roller on the belt is convex and was leaving a concave surface. I was not too confident in trying to use the table saw to shave them down, given how quickly things can go wrong there.
I ended up buying an oscillating spindle sander at Menard’s. With a guide board clamped to the table, it lets me feed the strips in and sand them down to a nice consistent .093″ thickness. It’s really slow going to try to do it all in one pass, so I set up a second guide board on the other side to knock them down about half way. One pass on one side, then a second pass on the other side of the drum and I have what I need. It still takes quite a bit of time. I installed the second largest drum, 2″ in diameter, but I think I’ll re-set it up with the larger 3″ drum instead. The higher speed of the drum surface may help to make it go a little faster, and the larger surface area might keep the drum from loading up or wearing out longer. With the shop vacuum sucking dust out around the spindle there’s virtually no sanding dust floating around, so that’s nice.
I got four strips done before I knocked off for the day. Doesn’t sound like much, but there was also a few hours of Pinewood Derby axle and wheel work in there, as well as some play time with the grandkids. Oh, and I did groove a couple dozen more rib capstrips too.
Tooling up (part 2)
I spent some time today going through the table saw setup and adjustment. As it turns out, my saw (a Ryobi BT3100) has a pretty decent following. I did figure out why I’d never been happy with the rip fence. I’d always used the grooves in the casting to align it. As it turns out, this saw is not like others. You don’t align the blade to the table. You align everything off the blade. I got the miter slot (an optional part), sliding miter table, and front scale all adjusted to the blade, lubed the jack screw that raises and lowers the blade, and checked the rip fence. Turns out, it’s pretty close to dead nuts on and always locks itself in place perfectly aligned… you just have to ignore the grooves in the table. Who knew? Anyway, I cleaned it up and gave the table a coat of wax, and cut a feather board and some trim strips for a remodeling project. It’s awesome. One down.
Tooling up (part 1)
If I’m going to be building something big out of wood, I’ll need to tool up for it. Right now I have some basic tools that will work, but what I have in the garage is more geared toward building an RV (and even a lot of those tools are now gone).
My bandsaw is a very inexpensive, small Harbor Freight model. I have tuned it up a little and adjusted it so that it works much better than it did out of the box, but it’s a very light duty saw. It’s also WAY too fast for cutting 4130 steel. I’ll need to at least get some good quality wood cutting blades for it, since it’s mostly been used for aluminum. I was looking for a better bandsaw, like a 14″ Delta or Rockwell, but I may hold off on that. This one might work, if I can come up with a solution for any steel parts that need to be cut.
The table saw I have is a fairly decent Ryobi. Not as solid or as precise as I’d like, but if I can figure out how to get the rip fence parallel to the blade it should be serviceable. But, for most things the radial arm should work anyway.
Belt sanders — I have two. One is a small bench-top Harbor Freight unit that is fine for very small jobs. The other is a 1950s vintage Craftsman that weighs well over 100# with its cast iron base and stand. I need to get it moved back home, cleaned, lubed and a new drive V-belt installed.
Drill press — The one I have is a complete piece of crap, and I don’t think there is a way to make it any better. I’m watching for a better one, preferably old and solid.
Chop saw — I have a De Walt 12″ compound miter saw. It works fine, but takes up a lot of space. In a shop environment I’d rather use a radial arm saw.
Radial arm saw — This could possibly be the secret weapon. I need to retrieve it from my sister’s place, but there is a Magna Sawsmith radial arm saw. My Dad used this to make a lot of furniture and other stuff, and it will do just about anything. My brother in law (ex, actually, but still a pretty damn good guy) told me the motor had burned out — I’m hoping it’s something more like a bad motor start capacitor, since those are easy to replace and the original motors are long out of production and nearly impossible (and expensive) to find. We’ll see how this one shakes out. Honestly, I can see myself taking on a lot more non-airplane woodworking projects if this saw can be returned to service.
Dust collection — I have none, other than a shop vacuum. The table saw, small belt sander and band saw all have dust collection fittings on them; the old (large) belt sander doesn’t. Not sure about the Sawsmith. I want to rig up something to suck up as much dust as possible, and I’ll for sure want to build a dust separator to keep from clogging up the shop vac.
Jointer/planer — I have none. I may need to fix that. This is an entirely new area for me, I’ve never used either tool and don’t know much about them. But, I may need to plane down wood for cap strips. We’ll see what the BOM that comes with the plans will reveal.