wing build questions

[High Country 69]

I have been making some good progress on my wings now that my new wing tanks have arrived, I got them all fitted up to the airframe last weekend and have now come up with a couple more questions, first my wife does not like the scalloped trailing edge that you get using the cable that came with my kit so I've ordered some trailing edge aluminum from ACS it should be here any day now. question do I just glue it on with Hysol or do I need to rivet it. Pictures would be good. I'm using speed wing ribs but building them to HH specs so with the narrow spacing do I still need the aluminum tube inside it to reinforce it or am I ok leaving off the extra weight. Next question my build manual says to cote all exposed wood with 3 coats of polyurethane before covering. is this still the preferred method or should I use a water sealer then polyurethane? Or maybe something all together different?

-Robert-

[akflyer 1427]

I have been making some good progress on my wings now that my new wing tanks have arrived, I got them all fitted up to the airframe last weekend and have now come up with a couple more questions, first my wife does not like the scalloped trailing edge that you get using the cable that came with my kit so I've ordered some trailing edge aluminum from ACS it should be here any day now. question do I just glue it on with Hysol or do I need to rivet it. Pictures would be good. I'm using speed wing ribs but building them to HH specs so with the narrow spacing do I still need the aluminum tube inside it to reinforce it or am I ok leaving off the extra weight. Next question my build manual says to cote all exposed wood with 3 coats of polyurethane before covering. is this still the preferred method or should I use a water sealer then polyurethane? Or maybe something all together different?

-Robert-

I used some 3/32 rivets to put mine on. Airdale cut them up and sent them to me in 2 1/2' lengths so I had a ton of splices to deal with also. I marked them and notched the bottom side to slide up the tails on the flaperon hangers then used hysol and the rivets every couple ribs to hold it all together. I think just hysol and covering will hold it in place from now till the end of time, but I put in a few just for shits n giggles.

I would dtill use the aluminum tubes! I used some minwax spar varnish on my ribs making sure to not get any on the cap strips. I used some left over epoxy primer on the rib caps just to seal them up.

[BryceKat 125]

Robert,

Polyurethane is a good flexible coating, not as tough as epoxy, but flexible, which is what you want because of expansion contraction etc. That is why they use it in auto finishes, etc. Bryce

[birddog486 21]

I used some left over epoxy primer on the rib caps just to seal them up.

Will this affect the strength of the glue bond to the capstrip? I think I saw in the manual not to put any paint or varnish on the capstrips do to the glue not being able to soak into the wood.

[Tree top pilot 13]

I used Hysol to bond the TE stock to the rib tails....ailerons and flaps in my case.

There is a Klingspor wood shop near me that stocks T-88 and all of the System Three adhesive line...up to gallon sizes. The general purpose resin is good to 165 deg. F. for service limits...so that is what I am going with to moisture proof the ribs. The guy that owns System Three is a home builder/pilot himself from what I have been told.

Nice work.....did you alodine your spar tubes? They have that golden tinge to them.

Edited 3 Aug 2012 by Tree top pilot

[High Country 69]

wow so many reply's so fast I love this place!!

I'm still leaning towards using one coat of sealer and two coats of polyurethane I plan to keep it inside an enclosed trailer out of the weather when not in use and I live in a pretty dry climate so this should serve me well I believe. Rivets and glue it is on the trailing edge and also the tube reinforcements guess all I need now is more time and parts.

Also no I did not put alodine on the spars the color is just the lighting on my porch, I was planing to just spray some primer on them after everything is complete just before fabric. is this a good idea or is there something else that I should use?

Thanks Robert

[EDMO 1078]

wow so many reply's so fast I love this place!!

I'm still leaning towards using one coat of sealer and two coats of polyurethane I plan to keep it inside an enclosed trailer out of the weather when not in use and I live in a pretty dry climate so this should serve me well I believe. Rivets and glue it is on the trailing edge and also the tube reinforcements guess all I need now is more time and parts.

Also no I did not put alodine on the spars the color is just the lighting on my porch, I was planing to just spray some primer on them after everything is complete just before fabric. is this a good idea or is there something else that I should use?

Thanks Robert

Answering this before looking at your photos - dont know what tubes you are referring to, but not a good idea to leave off something the designer felt was needed, imo,.

PRIMING the spars may not be good, depending on the glue and system you are going to use. The weight is neglible.

If you are using Stewarts, I would leave the spars bare - their glue will bond better. Others glues will eat up primer, and will only be safe on epoxy.

I used KILZ on ribs, and spray polyurethene 2 coats - masked any area where glue or fabric will attach to wood. If you finish your rib capstrips, be sure to sand them before gluing.

Congrats on progress.

Ed in MO

Edited 4 Aug 2012 by Ed In Missouri

[High Country 69]

Answering this before looking at your photos - dont know what tubes you are referring to, but not a good idea to leave off something the designer felt was needed, imo,.

PRIMING the spars may not be good, depending on the glue and system you are going to use. The weight is neglible.

If you are using Stewarts, I would leave the spars bare - their glue will bond better. Others glues will eat up primer, and will only be safe on epoxy.

I used KILZ on ribs, and spray polyurethene 2 coats - masked any area where glue or fabric will attach to wood. If you finish your rib capstrips, be sure to sand them before gluing.

Congrats on progress.

Ed in MO

I will be using the Stewarts system, I was thinking of masking off the front of the spars and the trailing edge where the glue will be just like I did the rib cap strips, then at least I can put primer on everything else to add just a bit of corrosion protection and the other areas will be covered with glue when I cover anyway so I figure that should protect it good enough.

[EDMO 1078]

I will be using the Stewarts system, I was thinking of masking off the front of the spars and the trailing edge where the glue will be just like I did the rib cap strips, then at least I can put primer on everything else to add just a bit of corrosion protection and the other areas will be covered with glue when I cover anyway so I figure that should protect it good enough.

Priming AND painting the inside of the trailing edges would be a good idea - water can collect there. I have been told that primer will not block moisture as well as the finish paint. I use the Rustoleum self-etching primer and enamel in a spray can is good enough. I've had bad results with their spray epoxy - turned out to be like powder.

Buy a pack of 100 seaplane grommets from Spruce, and put one everywhere moisture could collect. At the trailing edges, one near the outer rear of each rib would be a prime place to put them. After you are finished with your finish, take a real red-hot ice pick or small rod and go into each hole in the grommets and open up the fabric - dont drill it or you will leave frizzies which will trap moisture.

ED in MO

Edited 5 Aug 2012 by Ed In Missouri