scratch building and CA glue
 

I'm mack from near peoria IL, I'm just getting back into electric after twenty five yrs. but I feel like I'm new after so long and so many changes and improvements have happened, so I'll just post here in the beginners. I have built maybe five planes balsa, two of them scratch, Great Lakes trainer biper 40 inch, and the Fournier rf4, 72 inch. I'm building a 60 inch powered glider now, a Dale Black design, and I don' t mind saying its taking me a lot longer to put this together than it did in 1985... but one problem I still have wth the thin ca is it sticks the wax paper to your ribs and bottom spars and it's danged hard to sand this off... is there any new kind of see through paper that thin ca won't stick to? ..... also I'm looking to meet other e-flyers in the neighborhood who have time to kill. My e-mail is buck98@rocketmail.com. give me a whistle......

Hi :) You might want to try useing Saran wrap or clear plastic drop cloth, tape or pin it down over the plans, hope that helps, Chellie

http://www.ebay.com/itm/9-x-12-Drop-...item3a7b6ad9d6

Chelly, I tried the saran wrap, it works great. Thanks a lot! This will save a lot of work. And incidentally, I used the cheap dollar store saran wrap.......mack in IL

Nope saran wrap won't work ca will stick right to it. Get yourself some parchment paper in the bakery section of the store. CA won't stick to it, and it will protect your plans. Matter of fact I have rolled the parchment paper back up and reused it again.

My workshop has various types of CA, but what gets used the most is the old fashioned yellow Titebond carpenter glue. No stink, and after it has dried for 24 hours, sands like balsa. Also long ago I ran weight tests on CA vs Titebond. After a 24 hour drying period, Titebond is actually slightly lighter than CA.

Plus one on the Titebond I have gotten away from using CA for my Balsa builds that stuff gets used very little now. I have heard and read the same thing on wgt. gain using CA if you use a 1 ounce of CA it is a 1 ounce gain. While the water used in titebond evaporates leaving little wgt. gain.

Glad it worked for you :ws: I would try the Parchment paper too like Gramps says, i have not tried the bakeing paper, but i will give that a try too on my next build, Take care and have fun, Chellie

Wow I read his post wrong I thought he said it didn't work.:oops:
Me every time I tried saran wrap it stuck to it. I must be messy with that CA.:rolleyes::Q

+1 me too:rolleyes:
After just a couple years of using CA(at least weekly) it(fumes) gave me instant headaches.
It didn't bug me at first(now I use Gorrilla Glue Super Glue,not foam safe)but Denny, Joe and many other WF'ers made me a believer, its simply amazing how just adding a little water makes the yellow glue begin to cure and/or evaporate (less than 1 hour).

Saying all that, I did try med. CA on balsa and it soaked it all up in the wood, and in my very limited experience, I didn't think it bonded very well. Like it all got absorbed into the wood before clamping??
Maybe I'm not using enough!!:oops:or maybe I should've used thin...

IMVHO I like saran wrap, foam safe med CA just pops off for me...dunno...and its much easier to see thru, and to get more....I just raid the kitchen!!

BTW Tolona, you gonna do a build thread on that 60" glider??....balsa or foamie??

Welcome to WattFlyers, too!!

cr

with out a doubt this wrap is the very best to use as it lets go the balsa and ca .i use the wax paper also on top of the wrap i buy at art stores or walmart gift section.

my build table is covered in a 36"wide x12 yards long plastic wrap,the kind used on gift baskets. it's perfectly clear and very durable. if i rip it, all thats needed is plastic packing tape thats pretty much the same material.

i wrap one side around a pc of wood and screw it down on one side of the table, and stretch it across the table and wrap the other side around another pc of wood. with a few screws i can pull the plastic sheeting very tight and slip drawing under the front edge and build away.

one note,wax paper seems to be better coated with wax on one side more than the other....at least the brand i get at the supermarket seems to scratch differently with a finger nail on each side.i still use it on top of the plastic wrap for double the protection of the drawings and the packing tape holding down the wax paper releases off the plastic sheeting.

hope these pictures help and setup for a build takes all of 10 mins.

Gramps, I tried to stick balsa to saran wrap with thin CA, it won't stick. CHELLY's right. CA won't stick to baking parchment paper either, your're right on that, but baking paper is white, harder to see thru. Also. it's stiffer than s. wrap and tends to get air trapped under it like waxed paper. As far using yellow carpenters glue on balsa, ridiculous. who's got 24 hrs for glue to dry? The fact that thin ca soaks into balsa is the beauty of it. It doesn't just glue balsa together, it welds it, making a stronger and stiffer joint. I'm talking mainly wing work here where typically you're glueing the end of a spar to the nose, ca does it. Yellow glue doesn't work well on end grain because it won't penetrate as well. You can even glue balsa end grain to end grain. Take two sticks. of say 3/16" balsa, square up the ends and use thin ca, they're glued. I doubt that it's heavier than y.g. either. .

Patience is a virtue. Don't throw away your wood glue just yet. :)

I hate to burst your bubble but plain old yellow glue is quite strong. In fact they are generally about as strong as CA. And one HUGE advantage they have is they don't create the brittle joint that CA does. They are both roughly 4000 lbs/sq inch.

http://www.finehomebuilding.com/tool...late-glue.aspx

And yes while the wood glue is 24 hours for a full cure clamp set time is generally only 30 minutes. It is lighter - sands better and does not soak into the wood making it rock hard. It is also MUCH cheaper. And then you have the fumes and irritation to eyes.

When gluing balsa to other types of wood - aircraft ply for example wood glue is FAR better as the brittle joint from CA is quite easy to break.

I use 4 types of glue commonly in building. CA is great for certain situations but the others have their place too.

Mike

Couldn't of said it better Mike.
Myself never waited more than a half hour to gently handle what i am working on. As far as gluing end grain I just do what I learned from my wood working years. on the end grain apply a thin amount of glue wait and let it suck in. Then add some more and put the pieces together never had a failure at the glue joint.
We all have different ways to build and some of us want it now, and others enjoy the build part and just take are time.
I have built planes with CA when I started building thought it was the cats meow bang out a kit fast. Now I have learned to glue up a wing panel while that is setting I can move onto the tail feathers. Then it's back to the other half of the wing, or the fuse.
What ever glue you use and like that's the glue to use.:)

I use garbage bags as well. It won't stick, but if you use a lot of kicker it WILL melt the plastic when it sets off.

just my 2cents I use wood glue. has a little give, if you hit something easy nothing will crack. ca is brittle

I like to use CA as a clamp to hold the piece while the real glue, Titebond or epoxy or Gorilla Glue, cures at its own sweet pace. Just a touch of CA in the right place holds your pieces perfectly without pins or clamps.

+1 ... I'm one of those who tries to avoid over-use of CA ... it's convenient I know - but it has a distinct disadvantage :

Use of CA on balsa and other woods that it soaks into creates a hard stress point at the end of the CA. If you see a model crashed - usually the breaks occur right at those points. You have a sudden change in stiffness / hardness instead of the more flexible PVA wood glue type joint.

There's also the point that when repairing - a CA made joint can be a real pain to repair. It's so hard and permanent. A wood glue joint .. even epoxy ... can be stripped and remade. CA cannot.

My advice to any - leave the CA for repair work and 'helping hands' tacking. There are far better glues out there for full builds.

Nigel

I used to swear by CA, because that's what Dad got me into the hobby with. He grew up with slower glues but was using CA this evening when I walked past, so he's happy with it and I'm fine with that.

However, I started using Titebond because I felt CA was a crutch and that I wasn't a real modeler if I needed the "easy" stuff and couldn't do without. I _hate_ crutches.

I've gotten to the point where I don't even think about how much faster it would be anymore. I thought it would feel like it was taking forever but not really, it just makes me think more about the quality of the joint and causes me to be more methodical about the whole process.

I can't keep up with CA anyway. If I'm doing half decent work, I'm taking about 30 minutes between glue joints as it is. CA makes me feel slow. PVA fits into the slow nature of woodworking.

I stopped using CA altogether, it just feels like the easy way out of a hard problem, when I actually am tempted to use it. I don't like taking the easy way out.

I had forgotten that Titebond was lighter than CA... But I didn't care when I thought it was heavier! It's just more pleasant to work with.

I'll just not repeat what everyone else has said (Smells better, not brittle, sandable, etc...) and instead bring up my favorite part;

I always hated how plans where sacrificed when I built a model on them. No matter how careful I was, there would be that one little pin hole that the CA wicked into and glued the pin-board to the back of the plans, the parchment (Which is better than wax btw) and the model. That was a nightmare. On the model I'm building now (1/2 Astro Hog), I used Titebond and you can't even tell I've used the plans. That, by far, is my favorite part.

Yup
A wood glue joint glued with Titebond or yellow glue can easily be stripped out. Just aim your heat gun at it for long enough to cause the yellow wood glue to "Let Go". While still hot, gently pry the glue joint apart with a DULL knife or small putty knife. Same for epoxy, but DO IT OUTSIDE!

And, DO NOT do it with CA joints. CA will not let go, and heating it up generates all sorts of fumes, probably all bad.

I had a small 3 pound model where the 1 1/2 by 3 1/2 inch landing gear ply mounting plate came loose on what was really a pretty good landing. The LG and wheel pants went through the bottom and top of the wing.

The :censor: ARF model builder used thin CA on that ply plate. The CA actually only had glue adhesive on less than 10% of that ply plate. The rest had airgaps on the order of a few thousands of an inch, where thin CA won't work.

That LG structure was removed, and rebuilt using Titebond. Still flying that model three years later.

I can remember when Satelite City CA hit the model market ... we all went nuts for it ... but slowly people learnt it had it's limitations as pointed out in an earlier post of mine. In those days Kicker was basically not around ... that came later ... and was regarded as a 'cheats' way to save making a true fitting joint. As Denny says in the quote : airgaps ....

If CA does not make a bond - it's not CA at fault - it's the joint itself. Use of Kicker to remedy that in my book is a gross error.
Change to a better adhesive and that tiny airgap that failed with CA - suddenly will work with PVA, Epoxy, PU etc.

Yes - I admit that I have in past in those early years built whole models with CA .. but not now. I use CA eg : to tack a wing back together after a crash etc. - but when inserting new or doubling pieces - I use traditional glues to gain the flexibility / strength and benefits of them.

Nigel