glommes

Has anybody here ever tried utilizing the insulation foam in a spray can while building a plane? If you have any experience with this, please post your thoughts.
Specifically, I'd like to know if it is too heavy to be practical, if it is sticky and will work like glue to strengthen the frame, and will it withstand the heat from a covering iron?
Also, is it fuel proof?

RCKen

My Feedback: (9)

I don't have any experience directly with the foam, but I don't think it's needed. A properly built plane doesn't need any strengthing and the foam will only add extra wieght. IMHO you time would be better spent concentrating on the actual building of the plane.


Just my .02 worth

3dd

My Feedback: (6)

i use the latex water base spraycan foam around my fuel tanks sometimes and it works great and dosen't have a thing to do with way you build

the-plumber

Why is my building shop insulated with R-30 Pink Panther ?

Because the foam insulation I injected into the wall (once) popped a 4'x8' luan panel right off the studs.

Whut a MESS !!!!!

Gravityisnotmyfriend

My Feedback: (2)

"Great Stuff" that's what you need. If you're gluing foam to foam, it works...Great. It will fill the gaps between what you're gluing, it has about the same density as foam, and it's easy to shape and sand when it's dry. It is messy if you're not careful, and it takes awhile to dry, but when you're done its like you have one solid piece of foam.

Kaos Rulz

I used it once to further secure 2 oz of lead fishing weights I had coated with epoxy and dropped into a small hole on the underside tail section of a nose heavy plane. I felt Ok that the epoxy would hold the weights in place, but, I made real sure with a one second blast of canned foam. This stuff expands like crazy, so caution is in order to prevent you from eploding any seams. As a secondard effect, I noticed it did a fine job of further supporting flex rods between my braces. I guess if someone forgot to put in these support braces close enough to prevent bending, the foam would be the ticket.

FLYBOY

My Feedback: (11)

I have used it for a few things, and if you are not carefull, it will do more damage than good. If shot into like a fuse, and not enough expansion room is left, it will blow the fuse wide open. When it dries, it dries with a hard shell, but the center is softer and not easy to sand or shape.

All around, I would advise against it. It won't do you any good, its not needed, and it will not add strength like you are thinking. You can add strength other ways.

Turbobeaver

I agree with Flyboy.Don't waste your time trying to be inventive using spray can foam.More problems than it's worth and it's not going to do what you think it will do anyways.I had the "brainiac" idea a few years back when I was rebuilding my SeaDancer flying boat wing to try and strengthen the wings "D" tube area and give the wing more floatation in the event of a crash.The engine pod was mounted to the wing so in the event of a crash ,it was the wing that had to float well due to the added weight of the engine mounted to it.That was my thinking at the time.After building an entirely new wing(minus the L.E sheeting on one side of the wing) I set about using expanding foam to fill the forward "D" tube bays between each wing rib.I had used expanding foam before plenty of times so I was quite familiar with its expansion characters and the force behind it.Hence the lack of sheeting on one side of the L.E.After filling each bay with foam(kind of like making muffins in a muffin tin.......only less tasty[:'(]) I let it expand and set up.The idea was to cut off the over flow level with the top of each forward rib and then add the front sheeting and voila.NOTTTT!!!!!!I can't tell you how much of a mess this stuff is to work with.It just seems to get all over the place no matter how diligent and cautious you are.Cutting down the overflow was also an impossibility.I thought I could hot wire off the excess and give me a foam core type finish.Oh boy was I wrong.When that didn't work then I got out the long box knife blades and then proceeded to try and hack the rest off.Sanding this stuff?Forget it!Have you ever seen a grown man cry before?Oh yeah,before I forget to mention it,weight wise,you wouldn't believe how much extra weight this stuff can add.Yowzer!Well to make a long story short,this proved to be a utter waste of time and I ended up having to take Acetone to each bay and melt and wipe this crap out to try and salvage my new wing.What a !@!#%&*#% mess!!Good thing I'm as stubborn as a mule and have the patience of a cat or else I would have stomped the hell out of this thing that day I tell ya.After 1 litre of Acetone and an entire day of screwing with this dam foam and then having to remove it,I managed to salvage the wing and got it cleaned up again quite nicely.She was finished in the traditional fashion and went on to have a stellar flying career.R/C aircraft and expanding foam should never be used in the same sentence.........ever!!That's my soap box schpeel for t'day.Good flying guy's.

michpittsman

My Feedback: (11)

The "Great Stuff" foam is the stuff that expands with mucho gusto and will pop seams if you use a little too much; HOWEVER the same mfg came out a while back with a kinder, gentler foam that expands less. Check the chains for it. JIM

gow589

My Feedback: (1)

I use the foam you mix part A/ Part B. I have used it for many things. Here is a repair I used it for after a belly landing. Made the stringers but used it to fill in as suport:

http://www.rc-tech.net/bearcat/belly/b1.jpg
http://www.rc-tech.net/bearcat/belly/b2.jpg
http://www.rc-tech.net/bearcat/belly/b3.jpg

I have also found it as a great glue inside fiberglass airplanes. I have glued in gas tanks and other things like that. I tried making some molds and realized I could not get the foam to release. That is when I discovered it sticks to nearly everything. It fill as it does. This is where they came up with a modified version of it as "Gorilla Glue". I buy it from Fiberlay:

http://www.fiberlay.com/

gow589

My Feedback: (1)

I have also used it to stiffen large fiberglass cowlings. I glue a piece or two of wood in the cowling for rigidity then brush over it with the mixed foam. I have used it for 100 things. It is tool I could never give up.

Mike James

Good news/Bad news...

I've used 2-part expandable polyurethane foam ( http://www.fibreglast.com ) for a variety of projects, with varying results. The main issue, as everyone has noted above, is that you've got to make sure that expansion won't wreck what you'r doing. Generally, I've used it in an application where I had a keel and some formers, (and no sheeting or planking) and so the foam could expand freely. Later, I sand it back to the level of the formers, and glass it. The way to do it in a tight application requires patience. Build up the foam in small batches, rather than trying to guess the amount and do it all at once. Here are some examples:

1. Built the interior of a huge (90-inch) fuselage plug with it. ( http://homepage.mac.com/mikejames/rc...lugmaking.html )

2. Built an engine cowling plug and two large nacelles here. ( http://www.nextcraft.com/b200_construction03.html )

3. Built another large cowling with it here. ( http://homepage.mac.com/mikejames/rc...t_cowling.html )

4. Built a large canopy plug with it, here. ( http://homepage.mac.com/mikejames/rc...ut_canopy.html )

5. Built a fuselage with it, and this one did NOT work out. ( http://www.nextcraft.com/j47_sportjet02.html )

One of the "secrets" seems to be that this material needs to be stabilized immediately after a day or so of curing. All the projects above that worked out were glassed immediately. The one ( #5 ) that didn't work out was one that sat too long, and because the foam continues to cure for several days, it warped the part, and I had to remove the foam and resort to traditional methods. The canopy plug on this same project was made with the foam, glassed immediately, and it worked out fine.

Like any process, you'll have better results if you do some tests on parts that don't matter, before attempting something serious.

gunny11

My Feedback: (6)

Mike James, Love the work that you do.

Good pictures on your web site of all the projects. Keep up the good work.

Thanks,

Gunny

Mike James

Thank you very much. I appreciate the encouragement.

cheechukranch

I've used it to repair foam core wings and most recently to fill the chinsy plastic bits (wingtips and fairings) on my goldberg chipmunk. It's easily cutable and sandable. Contary to what people have said here, I thought it worked great. Hence the name...

jon595

My Feedback: (2)

I used it to secure the push rod tubes in a stick plane that I built. Shot some of the foam in at 3 different places, it foamed up and dried. The push rod tubes were totally secured. Then I put the top sheeting on. As the others have said, use sparingly because it will expand like crazy. I had a crunched wing on a profile plane (in the d tube part). The foam was injected into the cavity and it pushed everything back into place. Cut the excess that oozed out and recovered the bottom.

I knew beforehand how to use the product and have had good experiences with it.

kwmtrubrit

FWIW, There is a spray can foam out there in a blue and white can. I can't think of the name right now, but the foam is white in colour, isn't sticky like the yellowy foam and cleans up with water. Even the nozzle and tube can be cleaned with water allowing future usage. I've used this around the house and it doesn't seem to expand as much as the other stuff, is NO WHERE NEAR as messy, plus once dry the excess can be removed easily. I used a brush at the house. I've not used it in a model application so I don't know about weight differences between the two foams.

wascamp

My Feedback: (1)

I have used Canned foam as flotation in boat hulls and once or twice in airplanes. You need to use the low expansion type used to seal windows. It works great and is not as likley to blow out

rudderhinge

The blue and white can of foam sealant that kwmtrubrit is talking about is Dab Tex Mulit-Purpose Insulating Foam Sealant. It is a latex-based formula that will not overexpand and much easier to use than the yellow high expanding foam. It is white foam, it will clean up with water for reuse and it can be tooled or shaped while wet if done quickly. It is not fuel proof but it can be sealed with latex paint and then fuel proofed with polyurethane. I have used it on planes, boats, cars and my home. If you fill whatever you are working on about 90% it will not overexpand. At $3.50 a can, and you can reuse it if cleaned, its a good product for R/C use.

bretthan

How do you guys think the stuff would work for floats. Could you just make a mould and fill it with foam, smooth the top once dry, and then cover it in packing tape. How well would it hold wooden landing gear mounts in, and how long do you think the floats would last. O yah, how heavy is this stuff.

Gravityisnotmyfriend

My Feedback: (2)

The foam is cheap and so is packing tape. Give it a try and let us know if it works. Depending on ow much you allow it to expand, it wieghs about the same as styrofoam.
Cheechukranch, I'm with you. I've had great success with Great Stuff. As for the center being mushy and hard to sand, it will get as hard as the outside if you let it cure fully. Then its completely sandable.

Gravityisnotmyfriend

My Feedback: (2)

Check this out...
http://www.mhtc.net/~vweber/
All of the hovercrafts on this site are made out of foam and glued together with Great Stuff.

BWooster

It's not Dab, it's 'Dap'. The big difference I have noticed is that Dap foam stops expanding within a day of application. The standard polyurethane spray foams can expand for weeks-- no joke. (I've never tried either with airplanes, only to keep old man winter out.)

Canuck1

After reading Mike James's post, I thought I will have to try it. I have constructed a ME 262 fuselage that I was going to strip plank. It would take forever, so I decided to give his method a go. I used masking tape and so far 2 cans of expanding foam. I always wanted to produce my own fibreglass fuse so now I will with this method. So far so good. It is a big fuselage so it will take a few more applications. As you can see from the pics, I will need to go back and do some filling in. I will add more as I progress with it. I am in no means in a hurry as I am constucting something else at the same time.

50+AirYears

The instructions with the Lanier Comet recommended a low expansion spray foan in the tail. Messiest stuff I've ever used. Found almost every open seam and joint in that area. Even forced it's way under the masking tape I used for sealing. Only thing I use it for now is repairing crushed D tube wings.