If you are talking strip ribs for an I-beamer, I now make them out of fairly hard balsa because, using contest balsa, I would spend more time repairing broken ribs than installing new ones.  I have thought about doping on silkspan before slicing, but have never done it.

 Steve,

 No offense, but the existing rib strength is not the problem here. Sounds like you're at least somewhat aware of that. Unless the provided kit wood itself is way to soft 1/8" is definitely plenty thick. Many models use 1/16" ribs without issue. Trying to "strengthen" your 1/8" ribs in some way will only be adding a bunch of weight to the model that you don't want. It would also be a lot of extra work.
 
 We're not building Freight Trains here. You'll want to redirect your focus from this "stronger rib" thing. The best thing you can do is to teach yourself how to handle ALL parts in a less "ham-fisted" manner. Two of the biggest parts of becoming a better modeler is exercising patience and teaching yourself new techniques, to the point where they become instinct. A big one of those instincts that need to become programmed into yourself is using a delicate touch while building. Many times this is a benefit at the flying field too. It is possible, take a breath, s l o w  d o w n, and work at using a lighter touch.

 (BTW, cutting new 3/32" ribs would be going thinner than your 1/8" ones)

Steve, I have to agree with the above replies. But if you do decide to reinforce the ribs, dryer sheets are probably not right for the job. They are covered with antistatic something or other, and some sort of lubricant as a softener which I have always guessed is paraffin. So it may not stick very well. If you really feel the need to strengthen the ribs, the thinned white glue alone, lightly rubbed in with your finger is probably enough. Then you get the added fun of peeling the glue fingerprints off for the rest of the day.
Rusty

   1/8" ribs should be plenty tough enough, but if reinforcement is needed, I would dope silkspan on both sides of the sheet stock before cutting them out.

    Brett

  Now that I think about it they might be 1/16". I trying to get a Brodak Sea Hurricane to the point were I can get it off the bench. I had quite the time with the ribs in that kit. I'm in no way implying that either kit or manufacturer is to blame. I will take the advice of slowing down. I have tendency to build heavy as it is, so adding any unnecessary weight is not a good thing.

Steve

Thanks, I was going to suggest that.  Was told that years ago when we didn't have the good balsa in the kits.  Of course I question todays balsa as the parts and sheeting keep breaking across the grain.   Need to have a bottle of CA handy in those situations.   Am going through that now with two kits I am working on now.  Both by different manufacturers.

A strip of 1/16 x 1/4 (slice your own from scrap sheet stock), glued vertically between the spar notches would be enough, I think. If you have a problem with the aft end of the ribs, you might apply a coat of clear dope to both sides. Some give the entire rib a coat of clear, but remember to do both sides, or they'll probably warp.

Some of the FF guys cover both sides of a sheet of balsa with Japanese tissue/clear dope before they cut out the ribs, but their ribs are far thinner than those for CL stunt. Do not use dryer sheets and white glue.  Steve

Try building to music.

The expectation of the sound sometimes gives one a focus, same with shooting.

I do build to music, AC/DC, Metallica, Tom Jones, Blood, Sweat & Tears etc. Maybe I need something more subtle, oh wait I'm not trying to go to sleep.
Steve

I understand balsa can have wind cracks which go across grain.  I have seen cracks like that in contest balsa.  Maybe that is the problem, fixable to some extent with CA.

Hi Rusty:
I use a variety of sharpened tubes to cut the starter (end) holes. Then I connect the holes using a sharp #11 blade and a metal straightedge. The photos attached here should serve to explain the process. ...

Thanks, Bob. Those photos pretty much covered it. It looks like something I can add to my skill set right away.
Rusty

Bob
I typically use vertical grain balsa between ribs to turn the structure into a "D" tube. I usually end up with the rib split closer to the TE (behind the cutouts). Would another pillar there be worth the time(and weight)?

Steve

Now I have never tried this but ....... I have read about using an old chrome and steel telescopic car aerial as a set of balsa punches.

Just slide the interlocked tubes apart and sharpen the lower ends - the steel seems to be quite hard and should hold an edge.

And best of all it should be a zero cost item.

Oh, and Bob I love the light on a stick inside of your wing!

Now I have never tried this but ....... I have read about using an old chrome and steel telescopic car aerial as a set of balsa punches.

Just slide the interlocked tubes apart and sharpen the lower ends - the steel seems to be quite hard and should hold an edge.

And best of all it should be a zero cost item.

Oh, and Bob I love the light on a stick inside of your wing!

I do this with broken RC antennas, (back when everyone had 36mhz radios), but any telescoping antenna is pefect for small radii.

You lose strength.  When you just slap the shear webs onto the side of the spar the glue joint is very weak, and easily lets go in a crash or other high-stress situation.  This is pretty obvious when you look at a wing with such webs that has been thumped.

When you fit them up like Bob does, you almost don't need glue at all (don't anyone jump down my throat -- I said "almost").  The glue keeps the webs located in place, but the actual strength comes from the fact that you've got a rectangle of wood that's neatly filling a rectangular hole.

Note that to date I've been slapping them on the face of my spars, because I had been crashing all the time.  In this situation that's where you want them: when the webs are on the face of the spar, in a crash they break away before the spar suffers serious damage.  This would be dandy, but I've stopped crashing and now for the last year I've been flying a plane built with the philosophy that can be most easily stated as "it doesn't matter: it won't last the year".

Since my next plane may actually last long enough to show its flight time, rather than showing the times it's hit the ground hard, I'll probably do my next shear webs Bob's way.

Greengrocer's apos'trophe's removed, 14.2.4

Bob, that Lost Foam jig makes more sense to me for building a straight wing, checking as you go, than any other method I've seen. I recently got a rod-through-the-rib type jig, haven't used it yet, but it doesn't appear to let you check for twist, other than just hoping it doesn't spring into a horrid warp the moment it's released. I'm thinking of just building my upcoming Sig Skyray on the glass. I'll just trace and leave the prop tabs from the kit ribs on the balsa replacements I cut, and follow the kit instructions.

E-mail sent. Thanks,
Rusty

Bob,

I'm told you build and sell wings.

The wing that you have pictured, what would be the cost?

Measurements?

Thanks,

Charles

No offense taken, all the pictures and input is what I was looking for. I hope to start the next build(RSM Naughty Girl) in a week or so, maybe post some pics as I go.

Steve

As far as primitive jig I have you beat Tim. I use a melanine covered shelf with 90 deg. brackets attached at the rib stations. I just tape down the bottom spar and then clothespin the ribs to the brackets. Tack glue once I check alignment, then recheck before applying glue. Time consuming but, I know you can force wood  to conform to a jig. If I have anything really far out I make a new part.

Steve

I've been installing rib "pillars" to prevent C-Tube wings from crushing when building wings in my Lost-Foam system for more than 20 years. In that system we use weights on top of the top cradle piece to hold the molded shells in place while the glue dries. Tried doing that without the pillars and the result was a very thin (ahem) wing...

    Another advantage of the pillars on airplanes otherwise lacking shear webs is that it keeps the ribs from splitting chordwise from shear in the spars. I recently had the, uh,  opportunity to see the inside of the Skyray wing (balsa version). It is a C-tube with 1/8x1/2 10 lb spars set vertically at the high point, which means about 3/4" of unsupported balsa between the top and bottom spar slots. The spars themselves are pretty stout, but the airplane has always been prone to pulling an alarming amount of dihedral. easily visible to casual observers.

    When it was disassembled, the wing that hit the ground had every single rib (3/32 4.8 lb) split from the front clearance to the rear clearance. I then stripped the other wing which had been undamaged - same thing. I am pretty well convinced that the ribs all split there on the first hard corner. Bobby's pillar would have kept it together.

    The obvious question is, why no shear ribs? Thats because I wanted to be sure that the wing was flexible enough to take multiple crashes. That it did, easily 30-40 of them, with only cosmetic damage. Shear webs would have kept the dihedral out of it, but they also would likely have caused massive damage on a crash. At the least, I would expect the spars to have broken in a pancake landing, probably at the root. As it was, when the covering shattered, the spar broke right at the end of the center section sheeting - which made it to rigid.

   The stock wing was light ply and spruce straight out of the kit, and it was much stiffer (and absurdly heavier) It shattered in to MANY pieces on the first significant crash and was utterly irreparable. I threw the balsa wing together in about and hour and a half, and it lasted close to 20 years and multiple crashes. Maybe surprisingly, the original airplane was something like 5-6 ounces heavier than the rebuilt model, but with the 20FP it made nearly NO difference in the performance. Right to the end, it was limited by the tail moment and elevator movement, not the wing loading. But the lighter wing was far more durable.

    It may have survived this crash, too, if the Monokote had remained flexible like it was when new. As expected, in the pancake crash, it shattered like glass after sitting out in the sun on and off for 20 ish years. I wadded it up and it cracked into a million pieces. The covering on the bottom was a little stiff, but didn't crack and could not have a finger punched through it easily like the top.

     Brett

Perhaps a little tent over the plane... we could call them Brett Buck's quonset huts.

Hi again Bob.

I did not really mean to comment your foam jig system, it was more to those who use more classical wing jigs.
Another thing; if someone wants to optimize, the cap strips should have a stronger joint with l.e. sheeting than the butt-joint that everybody use. The strips should be recessed into the sheeting so that it has a good shear joint with main spar. Only then the caps can take all the loads they are capable of taking. I guess many of us have noticed how the wing stiffens when tip blocks are glued on. That just indicates that the ribs don't do their job properly.
Of course, our wings are so thick and weight/material volume is not such an issue. In free flight it is a big issue, if just one of about 100 ribs crack, the model becomes unflyable.

Lauri

Do you have a picture or drawing of this, not sure I understand what you mean by recess the strips into l.e. sheeting.

My guess is, this is what it would be.

And, of course, the TE also.

Don't forget the trailing edge also with cap strips.   

AND, you don't leave a sharp-edged cut in the LE wood to start a crack later.

   You absolutely DO NOT want to do what is shown in the drawing.

    Brett

I just want to make this "perfectaly clear" that the drawing isn't in any way MY recommendation on how to recess capstrips. The drawing was only in response to what was described.

Lauri Malila who, unless my drawing is incorrect, recommended this construction.

Brett makes sense, in that to cut a recess, there's two extra corners that could possibly crack.

Nice observation, Brett!

Edited, spelling error.

Actually, Brett made sense.  He has made sense since his first posts on this board.

Dick,

I heard NH had ploice dressed and armed as the Military would be. Like test marketing.

Is this true?