mmattockx

I have built a number of planes where I glued the templates to the wood stock with epoxy and simply cut out the templates to size, leaving the paper attached as a light reinforcement skin. Originally got the idea from the Boxer pattern plane series. Worked very well, but is messy and a nuisance to work with the epoxy. I have also used 3M-77 spray contact cement to stick templates down, but have never left those attached. Has anyone tried using a heavier coat of the 3M-77 to permanently stick the paper down and just glue to the paper when framing the fuse? It would be cleaner, easier and faster than the epoxy, but I am concerned about the joint strength doing this. Joint strength was never an issue with the epoxy. Alternatively, could the laminating be done with polyurethane glues? I have not tried them yet and do not have first hand experience with how much they foam with no extra moisture added to the pieces laminated. With extra water, I know they foam a lot, but without?


Thanks,
Mark

Dr1Driver

With only a LIGHT spritz of spray contact cement, the templates will easily peel right off. Why leave them?

Epoxy? Poly-U glues? What about good old CA? Nothing stronger.

Dr.1

mmattockx

I liked leaving them as they were a decent reinforcement, like a light fiberglass cloth laminated on. And it made doing cutouts and spotting formers dead easy. I like to laminate doublers on to the fuse sides, then cut out whatever needs removing from the laminated pieces. With the templates on it is just easier and more accurate to do. I have used the light shot of 3M-77 and it works fine, I was just wondering about the stength with a heavier shot. Maybe I need to bash together a simple box fuse and beat it up to see firsthand...


Mark

funkworks

I have had the best luck using a glue stick to secure paper patterns. It holds great and comes off fairly easily. 3M makes good glue stick and can be found in most stores. It doesnt take much glue either to secure the pattern. As far as laminating w/ paper, I would just keep it sinple and use a denser grade balsa of ply if I needed more strength. The paper might inhibit the glue from penetrating deeper into the wood (verses just wood alone) by soaking up the glue before it can get into the wood. Paper has better wicking properties than wood... I'm not a big fan of sprays since they can be so messy. Poly glues are still new to me. I dont like the idea of using water to get them to cure. Maybe someone out there has some experience with them.

mmattockx

The pattern guys are using them extensively now. See Mike Hester's Black Magic V2 build thread and Mark Hunt's Insight build thread for how much they use them. You don't need much moisture to cure the poly glues, just ambient humidity will often do it from what I've seen. I have yet to play with some, though, just too much work getting in the way of the important stuff right now. Terry Brox has a superb page on sheeting foam wings with poly glue and he has 450+sqin wing panels coming out at 8oz RTC! I believe he used something like 9 GRAMS of glue per side for a wing panel. Even with laminating resins, it is not possible to get that light and get a good bond, although some really good builders do it with 15-20g per sheet.

http://www.mackrc.net/patternwings2/index.htm


Mark

funkworks

Thanks for the link Mark. I will study it. I dont remember how many times Ive picked up a bottle of poly glue and them put it back on the shelf. Im going to have to dig into my scrap pile of wood and set up a few tests. I'm too chicken to try it on any current projects! I have heard good things regarding poly glues for foam core wing construction.

BMatthews

I would not want to trust the paper and 3M glue joint to hold well over time. You really should have wood to wood contact.

Even when using 3M 77 to hold the patterns on the wood for cutting down I'd suggest you only spray the paper and let dry to a tacky stick so that when you lift the paper that it doesn't leave any 77 behind.

Edwin

My Feedback: (2)

Me neither. I would never glue to paper left on the wood. I dont see any means of reinforcing. Its just paper. I always use the 3M77, just a light dusting so the template comes off after I'm done.
Edwin

mmattockx

That is my concern, too. Over time, the highly loaded joints may come apart and I am not interested in going there. I may try it on a small model and see how it does, then work up to bigger ones if it is successful.

That is the same method I used for sticking templates for cutting and it works fine.

Don't confuse the paper laminated on with epoxy with the 3M-77 version. The epoxied paper is as strong as the wood and has no issues pulling off. I was just trying to find a faster, cleaner method of permanently bonding the paper to the wood.


Mark

lilhachet

My Feedback: (2)

With the new poly glues, thats how they set up is with water. you glue one half and just wipe a thin layer of water on the other. The only thing with poly glue is it has a tenitsy of foaming up and expanding

ptxman

My Feedback: (2)

I always use paper templates from cad drawings > printer to accurately cut out parts on all sorts of materials. But I never leave the paper on. Its just non structural dead weight that will curl off over time. I use 3m-77 but actually I prefer a lighter strength one called spray mount. To remove I just give it a few drops of acetone, it wicks in the paper & it comes right off with minimal residue.

vertigo72480

Poly glues will expand. Regardless. You also have to use lotsa clamps to contain expansion. Not only that, they don't stay translucent. I use poly glues on furniture that I build, it's one heck of a bond. I have used it on a few funfly planes, but it's messy due to the expansion and I didn't care for the cleanup.

kdc

To stick paper templates to wood I use double sided tape- the type with a backing paper is best, Just use a few pieces about half an inch long in several places. Do not use too much or it is difficult to peel off the template.
Also the same to make two identical fuselage sides, just stick them together with a couple of pieces of tape and cut together. Works well and is not messy. Do not leave them stuck together for more than a few days though.

Hughes500E

My Feedback: (16)

I take my templates to a photocopy store, costs 2.00 bucks to copy everything using a laser toner copier, you can place the template upside down onto the wood and use Laquer Thinner to transfer the lines. After using this method with great success, I'll never do anything but again.