moneymaker

You can email me the photo if you want, [email protected]

MountaineerFan36

Thanks...I sent the pic.

RCKen

My Feedback: (9)

MountaineerFan36,
While it is best to make sure the top of the spars and the top of the ribs are flush when you assemble them, it's no big deal if they aren't. Sand the spar flush with the top of the ribs and you'll be fine.

Hope this helps

Ken

2slow2matter

My Feedback: (1)

As far as the spar goes--don't worry about it. one of three things has happened:
A) The spar is supposed to stick up a little, because when you add sheeting later on, it will all be flush
B) The slot in the rib for the spar was slightly smaller than the spar. It is fully seated, but isn't flush
C) The spar didn't quite get all the way into the slot, and isn't flush on the top.

In the case of B and C, just sand it of flush. You'd have to do some sanding on it anyway. This is where a long bar sander comes in handy! You might have to read further into the instructions to find out if the case is "A"

Dont worry about sanding it until the manual tells you. It will say to sand off all parts flush with each other. At that point, you will know!

If the case is "C", then when you can get to it, fill the gap between the spar and rib (where it didn't seat properly) with some thick CA. If you don't have thick, then fill it with medium, and hit it with some kicker. This will somewhat strengthen the joint.

BTW, if done properly, the CA glue will be much stronger than the balsa that it's joining, so don't worry about using CA--it works. Some people prefer not to use it. You make up your own mind!

Connery

I totally agree with moneymaker about using wood glue. In building my Top Flite P-47, I have use mostly Elmers Tite-Bond glue and everything is rock solid. While it doesn't set as fast as CA, that can also be an advantage. For instance, when gluing ribs into position, you can apply the glue, put them into place, get them lined up and make sure everything is exactly right before the glue sets. When you use CA, you have to make sure everything is exactly right before you glue it, and then hope it doesn't move when you are applying it.

MountaineerFan36

Thanks! Whew...I thought I had really screwed something up. I'll look through later steps in the instructions to see if scenerio A applies. I do seem to have a lot of balsa sheeting in the kit.

I need to refine my technique for appying the thin CA. This stuff seems to "pour" right out of the bottle with no pressure applied. I put a narrow tip on it to slow it down, but still seemed to get the stuff all over the place.

BTW guys......I'm having a blast building this plane!

Joe

bruce88123

Servo tube- It just looks to me like MAYBE the tube extends past the servo too far. If it is according to plans, no worry. I'm just concerned about routing the wires later. thought it slould be slightly more toward the root. Check plan and instructions.

Spar height- Looking at drawing labled "cross-section at W-3" I think it shows the sheeting butting into the spars, not laying on top of them. It's hard to tell from the small picture. take a close look at that part of the drawing and make a determination BEFORE doing any sanding.

Always be careful before removing material, it is hard to put it back on

moneymaker

Now there's anohter reason to use Elmer's yellow sticky nozzle

MountaineerFan36

You're right the tube does extend past the servo just a bit. I cut the end off at the second W-1 rib per instructions...but did not trim the end nearest where the servo is. There was nothing specific in the instructions that I can recall as to where this end should be trimmed. I was thinking of trimming it off at the nearest rib past the servo mounting area towards the root.

bruce88123

That sounds good. Make sure it is well anchored all of the way around the tube so as to prevent collapse at the entry/exit points. these can be firmed up with Ca as well.

As for using wood glue, I agree that it is good. I will often just barely tack a structure like a wing together with a minimum of thin CA and thin apply a fillet of TiteBond II to the joints. This has worked well for me on ribs and stringers and areas like that. You will develop your own methods as you go.

kerrydel

My Feedback: (2)

I use medium CA for almost all of my plane builds. There are spots where thin and thick work better, but I think medium is the right choice for 90% or more of the gluing. I find that thin doesn't bond as well because it won't bridge ANY gap at all, and thick doesn't penetrate. Plus, as you've noticed, thin CA is REALLY thin! I sometimes use wood glue for sheeting, but sometimes use "sheeting" CA (which is slower setting than thick CA).

In one of the manuals for planes that I have built (Sig LT 40 maybe), they mention having a fillet of glue in the joint. You definitely won't achieve this with thin CA.

I also use a fan to blow the fumes away as it will burn my eyes at times if I don't

Kerry

kluivertfan2

Thanks for this thread MF36. Im looking into building a kit soon, and have recieved numerous tips from your thread. Best of Luck to you.

RCKen

My Feedback: (9)

While you can use medium and thick CA to bridge gaps between parts, I feel that I should say this. It's best to have wood to wood contact. No amount of filling glue will replace the strength of having wood touching wood. Spend the time to try to get the 2 parts to fit tightly, it will be well worth the effort because the joint will be stronger. But yes, if you can't get that and there is a gap, you can use those to fill the gap.

Just putting my 02¢ worth in.

Ken

MountaineerFan36

I had to improvise a sanding block...so I cut off a piece of 2X4 and used thumb tacks to hold the sandpaper down. I'm sanding the trailing edge flush with the ribs. I got a little over agressive with the sandpaper and took a little balsa off the top of a few of the ribs. I don't think it will be much of an issue. I plan on using thick CA in the gaps on these ribs.

RCKen

My Feedback: (9)

MountaineerFan36,
Be careful when you go to fill gaps with CA. CA is very hard and is difficult to sand. That's another plus for using wood glue for building, you don't have the difficult to sand CA joints anymore. If the gap is more cosmetic than structural use wood filler to fill that gap. I use Elmer's Wood filler, but a lot of people use lightweight spackling to fill cracks and gaps. You can also use this filler to build up an area that you sanded too much off of.

Hope this helps

Ken

MountaineerFan36

Thanks Ken....the gap is really tiny and I just put a hair more CA on the top of those two ribs shown in the picture.

Question:


I'm on step 7 a. it reads: All of the wing center section sheets are cut from the 3/32" X 4" X36" balsa provided. Cut the top center piece that fits between the trailing edge sheet and the rear spar. Trim and sand the sheet to fit and glued it in place. SIG-BOND is recommended for gluing all of the center sheets to the ribs and spars as it is easier to sand the joints smooth.

First Question. What is Sig Bond...is this a type of wood glue?

Second Question. The instructions do not specify a length for the balsa. I took a few pictures and I think that the balsa sheeting should span the root rib and the following three ribs. This would make the sheeting flush with the main and rear spars if I span only these ribs. I would need to trim both the length and width of the balsa sheeting to accomplish this. Is this correct?

txaggie08

for someone who was this terrified of building, that looks pretty darn well built

RCKen

My Feedback: (9)

Here is what Sig's website say about Sig-bond

Now, to boil that all down. Yes, it is wood glue. Elmer's Carpenter's Glue and Titebond II are the same thing. When you start to do your sheeting this type of glue is GREAT!!!! You will need a way to weight down the sheeting until the glue dries. I have made a bunch of weights out of cloth and filled with BB's, but a lot of people will fill zip-lock bags with sand (double bag to protect against leaks) to make weights. Cut your sheeting to size, apply the glue to the ribs and your leading edge (some people prefer to CA the sheeting to the leading edge, but I don't. It's a personal preference), put the sheeting in place, and weight it down. If you do this before bedtime you can just go to bed and it'll be set when you get up.

The instructions may not say it, but look at the plans. They should show where the sheeting should go. I haven't built a 4*, but what you described sounds about normal for wing sheeting.

Hope this helps.

Ken

MountaineerFan36

Thanks Ken

I have no idea where it came from..but I found some titebond II out in the garage. Probably from some of my wifes craft projects!

BTW guys..let me know if I'm posting to many questions pics etc. I don't want to become a nuisance.

Skynyrd Man

Your doing a great job on the build, keep up the good work!
There is another method of sheeting that I was going to try when I build my Yak-3. I read about it in another thread.
In a nutshell you use elmers wood glue, put your beads down. Put the sheeting down, remove the sheeting. Allow the glue to dry. (I think a half hour) Re apply the sheeting and use an iron on the sheeting to get the glue to bond together. I could be wrong on some of this, I am going from memory which is useless.
Here is the link for the thread if you are interested in trying it.
[link=http://www.rcuniverse.com/forum/m_2502036/tm.htm]Yak-3 Build[/link]

RCKen

My Feedback: (9)

MountaineerFan36,
I would rather answer 5,000 questions from you than see you bring your plane home in a bag. We laugh about it now, but my flying buddies were almost ready to pull the cords out of their phones when I was doing my first build. I was calling them so much!!!! I think I can safely say that most everybody is cheering for you right now. I know I love watching your progress. Keep the question a coming. Remember, the only dumb question is the one you don't ask.

Ken

gboulton

My Feedback: (15)

Thanks for leaving this thread in the beginners area, mods.

I'm going to be following this one closely, Mountaineer...the 4* is one I'm seriously considering down the road as a second glow plane, and first kit...ood luck with her, I'll be eager to file away any tips revealed in here.

Rubberduck

Here's a pic of what the sheeting will look like. For reference, the right wing is in the foreground and the left wing is in the background.

Do NOT apply sheeting to the bottom side of the wing (ESPECIALLY THE CENTER SECTION) until after the wing is joined. If the wing is completely sheeted, it is impossible to apply epoxy to the dihedral brace. Yes...I'm speaking from experience!

If you have any other questions, just let me know. My 4* 60 is framed up and almost ready for covering, so I'll be glad to take any pictures or answer any questions.

flmlm

MountaineerFan,

Your doing a great job! In addition your assisting a lot of other folks as you go along. Just keep it coming and take your time. What you've done so far looks great. You've got a substantial amount of support here so just keep asking questions. What else can you do when you don't have somebody standing over your shoulder coaching you. This forum is for sure the best thing a person could ask for in this situation!

Let's go 'eer keep on keeping on! One step at a time. Continue reading those instructions, take the instruction book to work with ya.

Regards
Mike

IBrakeForNobody

My Feedback: (16)

Is that RCU in the backround?