Ok, so i seem to be running into some problems finishing this Sopwith pup.
I am trying to make templates out of cardstock sheets, so that i can cut the correct patterns for the metal sheeting that covers the nose area.

However, I am getting a small "pucker" when i lay the template down. No matter which way you smooth it, there will be a small pucker up in 1 area or another. I am only bringing it down to the edge of the bottom meets the side, so i am not trying to wrap underneath.

Does anyone have any suggestions as to how i can solve this. ??

I will attach a photo which i think is causing the problem, but still i am at a loss for a solution.

Thanks all!

what metal are you using, or is it silver colored covering? If you have any hint of a compound cuve, the card stock will not lie flat. Film covering should stretch/shrink into place OK. If it s aluminum sheet that you are putting down, it's going to be a lot like the card stock. You may be able to burnish it down though if the metal is soft and thin enough. It may be a tedious job, but you should be able to get it down. The ideal solution for an aluminum piece is a roll mill You may be able to tap a piece down on a big steel ball to get the curve you need. I have no experience doing that though so I can offer any tips on how to go about it.

One last option is to paint on the metal color. One of our guys did an awsome job on one of his planes. He used some aluminum powder and rubbed it into the still sticky paint. It looks like a real slightly weathered natural aluminum fuselage.

You may get some better recomendations over on the scale forum.

Last, great looking job so far. Really clean looking work.

Don</p>

There is a product I have read about here in RCU called Flitemetal.  Do a search and see what comes up.  I forget what forum or thread I saw it in but the models looked like the real thing.  It might be spelled Flightmetal as well.

You can cut your cardstock to the approximate size and transfer it to a piece of light aluminum sheet. You will need to work the aluminum to get it to lay in the correct position. Here is one thing that you have not considered. No airplane, especially a warplane from this era is too slick. They were not built to last very long, and were not pieces of art. They were very rough in places. If not that rough when built, by the time they got to a line squadron and the mechanics had a part off and back on several times, the part would be scarred, gouged, hammered and patched.

Bill, Waco Brother #1

I had not entertained the idea of the aircraft being built in the early 1900's i suppose it wouldnt be totally out of place to have some flaws in the metal.

I have 2 products i could use to cover, first is a very think aluminum flashing, OR i have a thin White plastic sheet, which i would then paint to simulate the aluminum.

Do you think it would be easier to use the plastic? perhaps i could then slightly heat it to form it to the contour i need, possible that would work..?

I like to use 3M (or any brand) aluminum tape. You can get it at Home Depot or Lowes...etc. It's adhesive is strong and Windex helps a bit to put it on. You can polish it after you apply it, or even beat it up if you like. If you make a mistake you can use a heat gun on low to peel it off and start over.

Campgems' response is good. Google 'stretching metal'. Get a plastic mallet and a nice hard flat area to do the whacking (anvil, 1/4 sheet steel plate, etc) and 'whack' gently the peice of metal in the center and toward but not to the edge in question. You will stretch the metal in the center causing it to bulge ever so slightly. If this is too much work then add Elmer's wood putty to that low spot and level it 'by judicious application of sandpaper'.[sm=idea.gif]

Plastic has a mind of it's own when heated. It shrinks, twist and does other undesirable things. You would need to fource it to the curve you want, and then hold it there until it was back to room temp, or else it will revert to the shape it wants.Covering like monokote or orakote are examples. Try shaping a piece that hasn't been held tight by sealing itto wood around the edges.Sheet plastichas similar reactionsto heat. If you could make a positive mold of the area, you may be able tovacuum form a piece of plastic to fit.

Don

Absolutley right, the plastic sheet didnt work. Even holding the shape firmly while applying small amounts of heat caused it to deform.

Is it possible to fiberglass the nose and get nice clean edges and then apply paint to that? Not exactly sure how i can get a sharp clean edge when glassing a single section
Im trying to avoid just simple painting of the nose because i need the raised effect to match the front hatch.

If i do have to settle for just paint. What is the process of building up the area with dope and Talc powder?
How much can you build it up and still be sturdy hard finish?
Do you have to use unscented talc, or will baby powder also work?

I appreciate any info

Trax, if I understand correctly, You want a metal pannel that hasa compound curve, with the sharp edge that you would expect from a metal pannel, or something that looks like that.

Fiberglass would work, but it going to take a lot of work to get what you want. It's kind of like making jewelry. To make a ring, you start with a block of wax. You carve and shape it to exactly what you wan't the final piece to look like. Then you invest the wax in a plaster of paris type stuff to make a mold of the piece you want. You then burn out the investment in a kiln. The wax is completely burnt out and you have a mold that you fill with molten metal that will look just like the wax you carved. Thinking along those lines, you could carve a plug that would be the piece you wan't. Make sure the details are them. From that plug, you would coat it with a mold release and then lay up a fiberglass covering on it. This fiberglass would be the actual mold that you would lay up your final part in. As much detail as you want can be included in the plug, and the final product will look like that. You will probably have some air bubles to contend with, but they are a minor issue. It is a lot of work for a one time project, but in case you want two or three, or more, you still have the mold.

This isn't a path I would take, Ihate working with fiberglass.I would just use a filler and build it up and shape it to what you what. The balsa filler will be to soft, but body putty for autos will let you file and sand to the shape you want and they will take most any paints you want to use after. It will probably hold up OK, but if you want a realy crisp sharp edge the won't chip wiht handeling, metal is the only way to go. I woudl suggest getting a roll of the aluminum duct tape and playing with it to see what you can come up with. Once you find how it works, then you can decide if it will do for the task at hand.

Don

http://www.flitemetal.com/

Give it a look.  They sent me a small sample amd I am sur ethey would do the same for you as well.  It really looks to me like it will do exactly what you are looking for.  Good luck

i'm assuming you'll be covering balsa or ply. if so, then you can use aluminum tape but you will still need to 'glass the balsa to get a smooth surface as the tape will show any and all imperfections in the balsa surface. i would go this route. to get the crisp edge you want, remove the cowl and tape any other edges that you don't want the epoxy or polyester to get to. then, after the 'glass/epoxy has cured sand the excess fiber from the taped edges to give you that clean edge. it will be much easier to smooth the 'glass around a compound curve than most other methods mentioned. also, the aluminum tape will also form to a compound curve with patience and practice. of course, using 'glass/epoxy will negate the need for the alum tape unless you want the look of unpainted metal or you want some wx'ing effects.

i did something very similar on my Fairey Flycatcher except i didn't mask the edges as i didn't need the clean edge prior to covering with Solartex. here's the link to my RCU thead showing what i did: http://www.rcuniverse.com/forum/m_14..._2/key_/tm.htm

hope this helps some.

I think i am going to try glassing the nose like you suggested Tubig.

However, I have the Koverall on the fuse and a coat of Nitrate. Can i apply the glass and resin directly over this?
Or do i need to cut back the Koverall off the area i am going to be glassing and perhaps sand abit of the wood to remove any nitrate??

Also for the tape i lay down to stop the glass from contacting area i dont want, will regular green scotch painters tape work?


Thank you

Trax,

Nice project!

You can lay a piece of plastic bag, black, over that entire area. Tape it on the other side so it is pulled drum tight. You can then lay light glass cloth over the plastic bag piece. Lay the glass cloth down, saturate it with resin, then place another plastic bag piece over it. Pull it tight like the first one. one layer could do it. This will give you a nice fiberglass piece that will fit perfectly. And after trimming, can be put in place with screws. I use Polyester resin. Repeat the same process on the other side. Might take two evenings, but what the hell.

Or. Sig makes a material that comes in sheets. You wet it. Forgot with what, cuz it's been ages since I've used it. Dries to the shape. Sig's deal is easy as pie. If they still offer the stuff?

Ever hear of gold leaf? Well, there's aluminum leaf. Google it. Easy to apply and looks like the real thing cuz it is!

Whatever you decide, good luck.

Charles

you may want to reconcider alum. flashing, go ahead and make your template as close as you can then transfer the shape to flashing. after you cut the flashing you can anneal the alum to make it softer with a propane torch, put soap on one side and heat the other side till the soap melts and turns black, then that makes the alum softer, then work the area to shape. may take several heat/bending attempts to get what you want.
after you get your panel on then work it over with steel wool start with 00 then progress to 0000. if you want a bright polish get some alum polish and go for it

hope this helps
todd

If i decide to glass the nose end permanently, can i apply the glass cloth and resin directly over the Koverall and Nitrate that is already there??

Or do i need to remove that section of covering to be on bare balsa. I dont know if the resin and cloth would adhere properly to the area if i leave the covering on it.

I think acetone will reduce both nitrate dope and epoxy so I would think it would bond OK.

since you have already covered the bare wood i wouldn't remove it especially since it might damage the Koverall that you want to keep. i checked a chemical compatibilty chart and you shouldn't have any problems with epoxy over nitrate dope. you will need to smooth out the Koverall area your going to cover as well as you can so that will make prepping the 'glass surface easier before you apply the tape if your going to do that.

you have a very nice model there. i would try these techniques on a scrap piece of wood (the same type as is on your actual model) complete with Koverall to make sure everything will work out as planned before you try it on the real thing. a couple of hours or evenings won't mean anything in the end.

as for masking tape, i use general purpose stuff. if it's real sticky i apply it to my workbench first to remove some of the tack before applying to a model.

For painted, raised panels, I simply mask off the area in question. I apply masking tape, in layers, to the desired depth. Using automotive high build primer (Rattle cans), the area is sprayed, in several coats, until the desired depth is reached. The painted is then sanded, and the tape removed.

This can be done, directly over your doped finish, as the prime is lacquer based, and will adhere well.

If you look carefully, you may be able to see yhe raised edges on the stab.

Trax,
i throw this out as another alternative to 'glassing your model. here's what i did with my Sig Cub on which i'm currrently working. the entire fuselage is covered in Koverall. i initially applied a couple of coats of nitrate dope to seal the fabric and later i applied a coat of lacquer primer and sanded to get rid of the nubs. last night i applied the aluminum tape. i still have to fill in the seams as this should look like one continuous metal panel. the dope and primer helped fill in enough of the fabric so that the weave did not show up through the tape. the one drawback is that the fabric won't prevent dents the way a 'glassed panel would.