Building a Sig 4*40....please support
 

I started building a Sig 4*40. Its my first kit as I have never built one before.

I started with the right wing. I made some progress over the weekend. I installed/glued all ribs plus the T.E. I am now ready to install the rear top sheeting. The instructions recommend using Sig Bond (Aliphatic resin) at the joint between the back of the sheeting and the T.E. as it is easier to sand. So now I have two questions:

1) My LHS did not have the Sig Bond so he sold me Titebond (not Titebond II). Is it ok to use it, or should I get the Titebond II.

2) Is this glue applied the same way with CA, i.e you fit the parts and then apply the CA to the joints where it will penetrate, or do you trial fit, remove the part, apply the glue and then reinstall.


Any help is much appreciated. Thanks

Note : I am trying to upload some photos but unable to do so . Will keep trying

RE: Building a Sig 4*40....please support
 

argileh,
First off, the glue you have will work just fine. You can also use Elmer's Carpenter's Glue too with no problems.

Second question, no you cannot use this glue like CA. CA is designed to wick into the joint between the two pieces and then bond them. With Titebond you are going to have to apply the glue to both sides of you joint and then join the parts together. Make sure you wipe off the excess glue that seeps out when you join the pieces. It's going to take about 30 minutes for the bond to dry to the point where you can handle it. The parts will have to remain undisturbed while the glue is setting up.

Hope this helps

Ken

RE: Building a Sig 4*40....please support
 

Any of the "white/yellow" glues are okay for what you are using them for. If you run a light bead on the top edge of the rib then carefully position the top sheeting piece over the ribs, then pin them in place to the bulsa sheet is held firmly down on each rib.

Do not get carried away with this glue, it can ad alot of weight to an airplane. The bottom ribs can be glued into place using medium CA, sparingly. I have also used medium and thick CA in the manner described above for the resin glue. If the CA is kept in a refrigerator, it will last alot longer, and also cures more slowly when it is cold. The advantage to using the resin glue is that it give you alot of work time and cleans up easily with water and paper towel. The advantage of the cold, medium or thick CA is that it dries much quicker, if you have steady hands, and can get the part in the exact location the first time.

I have built one of your airplanes from the box, ready to fly in less than 40 hours. It is a great, simple kit, with good instructions. I also built four 4*60's. I don't think I used any resin glue in any of them, just CA and 30 minute epoxy. I would never have been able to build so fast If I had to wait on the resin glue to dry on the wings and fuselage. None of the planes had any problems with glue joints and all came out very light, with great flight tendencies.

If you have any questions or other problems feel free to send me a PM and I'll try to get right back to you.

RE: Building a Sig 4*40....please support
 

argileh:

Congratulations on your decision to build a kit. I found it to be a very rewarding experience.
As far as the glue is concerned, I found that using the slower white/yellow glue was advantageous for me as a beginner because it forced me to slow down. It also fit my schedule quite well, since all I had time for was putting in and hour or two every night. This way, while the glue was drying over night I could start reading/planning the next step and not rush into the build.

I'm sure that more experienced builders can build successfully (as mikeboyd pointed out) kits from start to finish in 40 hours using CA, but you probably will be better off with the slower process of using your Titebond.

Just my 2¢

Good luck, and please post some pictures as you progress.

-tychoc

RE: Building a Sig 4*40....please support
 

Plus Tite Bond and similar glues are not going to bother your lungs and eyes (or at least shouldn't). Don't recommend drinking it though. :D CA fumes really bother a lot of people but not at all some others.

Good luck on your build. Take your time and ask your questions here.

RE: Building a Sig 4*40....please support
 

I used to use CA to build but I switched to Elmer's glue. First off I didn't like what it did to my lungs, the fumes were to harsh. I also didn't like the hard knots that CA left on wood. Joints glued with CA are just plain hard to sand because they are harder than the surronding wood. Since I've switched I feel that I'm a better builder, or at least I am getting better results when I build. The extra time it takes wood glue to set gives me time to make sure that the parts are positioned correctly. Also the joints are easier to sand. And the time it takes for the glue to set doesn't really slow me down any. With a little plannin ahead and I can be workiong on another assembly while the one I just glued dries.

Hipe this helps

Ken

RE: Building a Sig 4*40....please support
 

I am trying again to upload the photos, I hope it works this time. The sheeting is still not installed.

RE: Building a Sig 4*40....please support
 

Looks great[sm=thumbup.gif][sm=thumbup.gif]

Scott

RE: Building a Sig 4*40....please support
 

Looks good so far. :)

RE: Building a Sig 4*40....please support
 

Thanks guys, I feel good now.

Tonight I will glue the rear top sheeting with Titebond. I will post pictures. Wish me luck

RE: Building a Sig 4*40....please support
 

Argileh,

Here's a mod I wished I had done when origially building my 4 *. When it comes time to hinge and mount the ailerons, add an extra hinge one bay in from the wingtips. The 4 * really floats and it's roll rate is a bit slow. If you add the extra hinges now, in the future, you can shorten the wings and have a hinge already in place to support the tips of the ailerons. Shortening the wings is a common mod to increase the performance. I shortened the wings on my 4 * for it's second season of flying.

Scott

RE: Building a Sig 4*40....please support
 

I have managed to find some time to make small progress. I have installed the rear top sheeting, the shear webs and the top main spar. Enough for today. The L.E., forward spar and top sheeting will hopefully be done over the coming two days. I then will be able to unpin the wing and install the bottom sheeting. My challenge will be sanding the L.E. and T.E. as I have no prior experience and I am a bit nervous, I really do not want to make a mess. Any suggestions.

RE: Building a Sig 4*40....please support
 

A long sanding bar would sure help.

http://www2.towerhobbies.com/cgi-bin...&I=LXK315&P=ML

or

http://www2.towerhobbies.com/cgi-bin...&I=LXK315&P=ML

with
http://www2.towerhobbies.com/cgi-bin...?&I=LXK320&P=M
http://www2.towerhobbies.com/cgi-bin...?&I=LXK321&P=M
or others.

RE: Building a Sig 4*40....please support
 

Get the 22'' one and cut it up into smaller ones. You could then make a 12'' one plus 2 or 3 smaller ones.

-tychoc

RE: Building a Sig 4*40....please support
 

I have been building for years and always started with 80 grit and moved my way to 320 grit.
I purchased a Razor Plane from the LHS made by Master Airscrew. It works great and makes
those major shaping jobs a lot easier. Wish I would have had this 12 yrs ago when I started
this hobby. Would have saved me a lot of sanding.

I recommend one of those and the Great Planes Sanders are excellent. When you buy the
5.5" ones they come with an assortment of sanding paper. I bought 3 when they came out
and keep each one loaded with a different grit. Saves time changing the paper when you
need it.

I am about finished with a 4*60, it looks like a totally different wing structure than the 40,
more spars, I figured it would be just a scaled down version of a 60 size.

If you need any help or get stuck there is a TON of guys on here to help. Just ask, and
remember there is not a stupid question.

RE: Building a Sig 4*40....please support
 

These are also very nice tools although pricey.

http://www.centralhobbies.com/Tools/permagrit.html

www.bvmjets.com also carries them and I'm sure others. As I said, nice but pricey.

RE: Building a Sig 4*40....please support
 

Thanks guys for all the help. I already have the necessary tools (Great Planes 5.5" sanding bar, sand paper, whittling blade...). It's just that I am a bit nervous about shaping the L.E. to a round profile. I am afraid I might ruin it. So I am after some advice on how best to do it.

RE: Building a Sig 4*40....please support
 

Start with the general shape using your blade or like I recommend a razor plane.
Once the general shape use 80 grit paper to get it to a rough shape. Then work
your way up to 150 then to 220. Save the higher grits until you are ready to cover.

When making a round shape that is consistent I sand back and forth and move the
block from one side to the other forming the round shape (I cant explain this part
very well). Make sure not to stay in one place too long, if you do you will have a
flat spot.

Another neat tool I recently invested in was the multi-sander from Great Planes.
There is a contour for the leading edge of a tail surface, a triangular contour and
one for a leading edge. The leading edge part is only valuable if your leading edge
is that contour.

RE: Building a Sig 4*40....please support
 

You can take a piece of cardboard or something else stiff and make a template from the planes and use it as a guage when sanding.

RE: Building a Sig 4*40....please support
 

Yesterday when I installed the top main spar I tacked it in place with thin CA. Today I came to apply medium CA and I realized that at some places the spar is not absolutely flush with the the top of the rib ( the spar is about 1/32" igher than the top of the rib). I dont know why this has happened, I worked hard to make sure that the spar sat all the way down the notch in the rib. Is this a problem. Do I have to take the spar out, or is there a way around it. I thought about sanding the spar a bit.

Your thoughts please.

RE: Building a Sig 4*40....please support
 

While the best would to have had the spar sitting in the "bottom" of the notch in each rib, it's not going to be a big deal if not. You would probably cause more damage by trying to remove the spar than if you just left it. Since you're using CA for your build, run a bead of thick CA where the spar and rib meet. Or even a small bead of 5 minute epoxy will do better. Just get something there to stabalize the spar and rib. You'll be ok. Chock it up as a learning experience

Ken

RE: Building a Sig 4*40....please support
 

Ken, I think he is saying that the spar sticks up above the ribs instead of being flush. IOW, the covering will not contact the ribs near the spar and any sheeting may also not fit correctly.

argileh - did you clamp everything in place or just rely on the CA. Are you just using CA? Do you think you could relocate the spar if you used CA debonder to loosen the current joints? Maybe apply a little clamp pressure while applying the debonder until the spar shifts? Then reglue as needed. Let set before removing clamps.

I still like my Tite Bond II for this stuff but not on top of C

RE: Building a Sig 4*40....please support
 

Bruce,
Duh on my part. That'll teach me to not do two things at once, watch tv and answer RCU ads!!! :D

Ken

RE: Building a Sig 4*40....please support
 

I just got done framing one of these up myself. I ran a bead of Wood Glue (great planes variety)
along the spar webs and the ribs. Put the spar in and used something to hold it down. Still have
a small ridge but nothing some masking tape on the ribs and a sander cant fix to level it all out.

RE: Building a Sig 4*40....please support
 

When I installed the spar I applied thin CA while applying a down pressure on the spar to make sure it went all the way down, so it did not come loose and rise after applying the CA. I thnk right now it is all the way down as it can be. The only explantion is that some of the shear webs need more sanding to make them flush with the notch, although I am almost certain I did that before installing the spar.