picard1

My Feedback: (2)

Since I live in an apartment I don't have access to 200 pounds required to attach the sheeting to the foam core fusalge, well, I do have a refrigerator!!!! What else can I use? I read somewhere that 3m spray adhesive works.

Looking for suggestions?


Mike

Paternguy

My Feedback: (1)

Finishing resin works good, you could try using tape to hold it in place, however you may end up with waves in the sheeting, the best bet is to use the weight.

majortom-RCU

My Feedback: (40)

We used to use Southern Sorghum pressure sensitive adhesive, and that always worked well for me here in New Hampshire. I have seen comments that it would bubble up and delaminate in hot weather, but I never experienced that. I now use vacuum bagging for my pattern projects, but if I were doing foam cores in an apartment I would not hesitate to use 3M foam-safe pressure sensitive spray. I use it for gluing foam blocks together, and it holds very well.

The trick is to get your balsa skin lined up on the foam core with a sheet of wax paper separating balsa from foam, then slip the wax paper out without moving the skin off the foam core. Actually you can slip out a couple inches of the wax paper, then lightly set the edge of the skin to the core to keep it steady, then slip the paper out in steps and lightly tack down the skin to the core as you go. First adhesion should be the high point along the spar, then put the skin side down and roll it forward and back to stick the whole surface, being careful to rock the entire length of the wing panel without introducing any twist along the length of the wing. Maybe sounds intimidating, but I did it the first time without any problem and many times since.

After the entire surface has been tacked together, run a trim paint roller over every square inch to get good adhesion throughout.

STLPilot

My Feedback: (21)

Picard I don't think you want to glue the fuse without weights. I've seen pictures with people that use lots of different things to get to the 200 Lbs. If you live in Apt. complex see if you can call the maintenence guy and see if he has any bags of cement or something. Books is real popular too.

The most important thing is that your base must be very flat and very solid.

AFSalmon

My Feedback: (3)

From lots of experience I would not recommend spray adhesive. You will never get the kind of bond you do with quality adhesives such as urethane glues or epoxies. You can use thinned epoxy resin as suggested above. In that case you won;t need massive amounts of weight like you do for the expanding urethane glues. Just enough to hold everything flat and still. Get a flat board to cover the fuselage sandwich and several stacks of books like Dion suggest and you should be fine. If you use a urethane glue like Gorilla glue, then you will need more weight. i like to use water softener bags as I've always got a need for them. Even if you don't have any maybe a friend with a water sofener can buy 5 or 6 and let you use them temporarily. i like this approach since you don't have to store the weight!

famousdave

My Feedback: (61)

As far as I am concerned the only way to get a really solid bond and keep the structure light is to use probond and a vacuum bag. You can apply well over 40PSI using the vac-bag. You would need 500 pounds of weights to equal it.

If you build a lot of foam sheeted planes this is a no brainer..

DP

Spacey

Mike has a good point regarding the epoxy. I used the thinned epoxy method on my Ultimate and you really don't need alot of weight with this one. Most important thing is to keep everything flat and spread the load a little. But much less weight is needed to force things together. And the epoxy dries fairly quickly so you could just sit on the thing yourself if you can spread the load a little heheheh..No seriously a flight box, pile of books, the microwave...you're set.

AFSalmon

My Feedback: (3)

DP, you are absolutely right. I did not mention the vacuum bagging since most people don't have the equipment or experience to do it that way but that is very popular especially in glider wing construction. When using weights I recommended above using a long flat board over the fuse first. This allows you to evenly distribute the weight much better like Spacey mentions.

picard1

My Feedback: (2)

What ratio should I thin the epoxy to?


mike

AFSalmon

My Feedback: (3)

Good question but I don't know. I have always used the probond or gorilla glue for my foam core sheeting. Anybody else?

Spacey

There is a ratio? Terribly sorry I always TLAR the stuff? Heheheh...It's hard to say but I would say add methylated spirits untill it becomes fairly watery. Sometimes the epoxy won't dissolve completely in the spirits and then you have too much in there. BUT!! The spirits evaporates very quickly so it doesn't matter! Just make sure that after you have spread the entire foam surface that you can see the kind of shiny layer of epoxy on it. If you lightly touch anywhere on it you should feel it being slightly sticky. Then you know you have enough epoxy on it. PLEASE PLEASE PLEASE do not spread the poor thing so it make a 1/16" thick layer of epoxy on it! It is NOT needed. Depending on which plane you are building you will need quite a bit of epoxy though. It's very hard for me to explain because I always just guess the stuff but if it's Great Planes 30minute epoxy you are using I am sure you know the stuff is quite thin and spreads into a puddle of about a 1/4 inch or slightly less very quickly. Now see after both parts are poured out or mixed I would say that puddle should be about 2" or slightly more in diameter? Does that make sense? Give you an idea at least? It's quite a bit of epoxy I know.

You know ultimately thinking about it you can chuck alot of spirits in there. It will evaporate so quickly when you spread it out that you will very quickly be able to see the shiny surface the epoxy makes. Just make sure you stir the whole mixture very well before you dip the brush in. And check for that shinyness the epoxy gives after you spread the whole thing. You will quickly be able to see it after the non epoxy containing spirits evaporate.

Edit: Oh when I talk about the amount of epoxy I am thinking about the .40 sized OMP profile fuselages and only covering ONE side of the fuselage. I always glue one side, then let it dry in the press, and then the other to make the epoxy mixing thing easier.

Paternguy

My Feedback: (1)

Use finishing resin, you won't have to mess with thinning out regular epoxy, and you don't run the risk of the epoxy foaming and bubbling up if you happen to get a little to much moisture in it.

Try This :

http://www2.towerhobbies.com/cgi-bin...?&I=LXK304&P=7