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1st time using T88

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Franklin63

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Sep 26, 2010
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Hello,
I am starting a Fisher FP202 Koala project and I am hoping to get some advice here.
The FP202 very strongly resembles a Piper J3Cub, but it is only about 1/3 the size and is wood.
So, I am starting the build with the tail section.
Today I built the jig for the 5-layer lamination of the 1/8" x 3/4" x 8' strips.
These strips, once laminated, will make-up the curved trailing edge of the rudder.
Everything is set up nicely over the plans with wax paper and I am ready to go ahead and glue the strips but I am hesitating because although my test fit looks really nice in the jig and it is all clamped-up I know that it will be a different story when I go to glue it.
My questions are:
Has anyone here done this multi-layer lamination or something similar? What is a good process for gluing the strips and getting them into the jig?

Thanks in advance for any help.
 

wally

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southwest TN.
I have used T-88 some years ago. Mitchell wing B-10.

What you are doing is not too hard. I found T-88 easy to use. You could lay the strips flat and glue and stack them first then put in your jig or put the strips one at a time in the jig. You will find the strips want to slide around with glue on them so be ready for that. There should be plenty of open working time to get this job done. If you have left the strips in your jig dry - no glue- for a while, they are probably already taking a set to the desired curve which will help a little too.

Just as long as each mating surface gets a nice even swipe of glue and you see some squeeze-out when in your jig, you should do fine and will have a good part. You do not need a huge amount of clamping pressure, just close the gap evenly along the part. After it has cured, you will be able to clean off the dribbles and sand to final shape. A disc sander or belt sander will work fine. Go slow and the excess glue can be ground off with not much trouble.

And as you are the builder, you are also QC inspection. If you don't like the finished part, don't hesitate to trash it and make another. That way when you completly finish, you can sleep at night and not be worrying "what if" all the time.

Good luck!
Wally
 

steveair2

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Here is one of mine. It is not difficult. I use a acid brush to spead the glue. The outside row of nails is put in, then the strips are put in and glued one at a time. Each strip is held with pvc clamps. The clamps are removed and repositioned as each new strip is added. Once all the strips are in I add a second inner row of nails and then reclamp.
 

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Franklin63

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Central Texas
Thanks you guys.
That makes me feel alot better about going ahead and doing it now. Thats what I was trying to figure out wally: Do I stack and glue, or do I put them in one at a time?
I'll do one at a time.
I was worried about how much time I have while the glue sets because I am a slow worker and I don't want to get flustered and make a big mess. Temp is mid-upper 80s where I am, and humid. Hot garage.
I spent 6 hours making the jig. I am not in a hurry.
I like the PVC method steveair2, I am going to do just what you did.
What a relief.
 

steveair2

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Looks good Franklin. I thinned my mixed T-88 with a touch of alcohol. Makes it easier to brush on and seems to lengthen the pot life a bit. You still will have to work fast for a lamination as large as your rudder trailing edge.
 

wally

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southwest TN.
It does look good.

Here is another thought. If you find you are really running out of time with the glue getting too stiff to work, just laminate the first couple of strips and stop. After it cures, clean it up and add the other strips. Just maintain the inside curve to match the pattern with the first strips and add the rest to the outside the next time or the other way around.

And invite some help if you can to aid in tightening all those clamps.

Oh, and another thing I just thought of (except now looking carefully at your picture, you would have to re-do your board). Cut a scrap piece of plywood or similar in the general shape of the curve so the part is supported and yet the little clamp handles hang over the edge.They can be turned a lot faster if you can just spin them instead of making half a turn, slipping the handle through the hole and turning another half. Maybe a thought you can use next time.
Wally
 
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Franklin63

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Central Texas
Wow wally, a few days ago I had the idea of doing just-that but nobody suggested it til now. I can laminate 2 layers, let it cure and then laminate more later and so on. Glad you mentioned it because I think I'll do it that way. Especially when I get to the stab and elevator. The stab is 8 layers of lamination! and alot longer. And about the c clamp suggestion, I have the rudder on a 36" interior door that I bought brand new. It was the flattest thing I could find. I screwed some 1/4" plywood over it. But I like the idea. Good advice.
Well, I went ahead and did a practice glue today. I made a mock-jig and lammed some strips
for training purposes. Now I know the glue somewhat, and I will know more what to expect when I start. I like the glue. It's user friendly.
My practice jig:
 

Franklin63

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Thanks for the kind words shafferpilot. I thought people would think I was some kinda nut for doing that and wasting glue. But that little practice piece ended up so strong I couldn't believe it. I tried to brake it like a big wish bone but no way. Real strong stuff that T-88. So I glued up my rudder edge tonight. I was checking my watch alot. I kept a steady pace and it ended up a little messy but okay. I had plenty of time after all. I Got the glue applied to every surface of the 5 layers. I used a small brush and also spread it with my finger to make sure it got on every bit of both surfaces. 55 minutes for applying the glue. Clamped it but not too horribly tight. 90 minutes from start to finish. . Now I'll feel alot better about starting that stabilizer later on.

 

rheuschele

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Chicago Il. USA.
Looks good Franklin. I thinned my mixed T-88 with a touch of alcohol. Makes it easier to brush on and seems to lengthen the pot life a bit. You still will have to work fast for a lamination as large as your rudder trailing edge.
I'm curious, who told you this was not only acceptable, but safe?
 

Franklin63

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Well that did'nt work too well. All those little pieces of wood that I placed in there between the c-clamps and the clamped-wood ended up glued so dang good to the rudder edge that I damaged it trying to remove them. I had to toss it and re-do it. I also noticed when my glue bottles settled that the hardener had about 1/4 inch more than the other bottle. Oh well, lesson learned.
I made the jig too complicated, forgot the rule. Keep it simple. Now I have it clamped up with No-other -wood touching it at all. Just metal clamps lightly tightened, nails and some of those PVC clamps. Pretty neat idea btw steveair2. Thnks.
 

steveair2

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Looks good Franklin. I thinned my mixed T-88 with a touch of alcohol. Makes it easier to brush on and seems to lengthen the pot life a bit. You still will have to work fast for a lamination as large as your rudder trailing edge.
Oops! Thinning T-88 will decrease it's strength. May also have other ill effects. DON'T DO IT !
 

PTAirco

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Go buy the mixing gun, it's worth every cent. It now also comes in a cartridge that fits a regular caulking gun, and you just fit the mixer tip. It's the only way to go with this stuff.
 

wiloows5050

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Try finding a small roller to apply the glue. Check the hardware stores for a trim kit. Or you can mix some up and put it in a small squeeze bottle i.e. mustard, that way all you have to do is brush it flat. Don't forget wax paper on anything you don't want glued to your work.

Don
 

Franklin63

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Central Texas
Oh man that is a good idea. I can mix it in a squeezeable mustard bottle and then all I have to do is lay a bead and spread it.
I will definitely do that.
I still have a lot of laminating to do. That will help and I will also waste less glue.

There is a lot of good stuff on this forum.
:grin:
 

Franklin63

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Central Texas
How would you guys suggest rounding-off the edges of my curved laminated piece?

My plan is to use a 'thumbnail' router bit I ordered. It puts a half-oval shape on a 3/4" edge. I want to round the edges BEFORE I build the rest of the rudder. Same goes for the stab and elevator. I have noticed in pictures that some guys are rounding off the edges AFTER they build it. I don't have a good feeling doing it that way.
 

deskpilot

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Although I've not built a plane of my own, I thought this might be adaptable to you're, or others, problem.

As a kid, I did a bit of 'steam bending' when making a coffee table, the legs of which were nicely bowed. First, in order to get two sets the same, a jig was built around which the steam softened wood was to be formed. Next we made a tin strap with wooden handles which was to to be used in pulling the wood around the jig. See attached image.
When in use, no clamps are needed on the curves portions, only at the very ends. In your case, a couple on the straights might be advisable.

PS in the note on final image, the word should be 'stack', not stake.
 

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wiloows5050

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Try a beltsander but watch how much you take off. Don't be too aggresive especially if you are using coarse grit. I'd do a little with 80 then switch to 120 and finish up with the routier and a finish sander.
 
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