grahamd1

My Feedback: (1)

English Electric, in the UK Z-poxy is available (imported by Macgregor Industries).

The most common UK types of epoxy are

Pacer Z-poxy finishing resin
Ripmax Epoxy resin
Chemi-techniques finishing resin

However my own prefference is with West Systems, this can be purchased from any Chandlers (boat builders/suppliers), its great stuff.

English Electric

Thank you. I will try and source the resin.

grahamd1

My Feedback: (1)

This is the UK site where the UK products have been tested

http://www.*************.co.uk/4um/

newbiepilot

Ok, so Spackle is just premixed resin and microballoons, right? Does it have any strength in it? Could you use it to join parts together?
Thanks for the info.
I really appreciate it.

davidfee

No, spackle is not resin and microballoons. Lightweight spackle is water-based... probably an acrylic latex base of some kind (don't have a container of it to look at). It does not have much strength at all, as it is only used to fill small holes and sanding scratches. It would not work as an adhesive.

-David

FLYBOY

My Feedback: (11)

As stated, don't use spackle as glue. It has not strength. I use it for fillets, but when they dry and are shaped right, I go over them with CA. Also, I use micro balloons mixed with epoxy. It makes good fillets, but you need it right, they don't sand well. You end up sanding the balsa too much and the glue not enough. I lay in the mix, put alcohol on my finger and smooth it to perfect and let it set up.

Mixing micro balloons in wood glue doesn't work well. The balloons suck up the moisture and it makes a mess. I have never had any luck doing it. You can try, but I think you will find the same.

newbiepilot

What did you mean by this then:

"Spackle is the putty you fill pinholes in your walls with (in your house) before painting. Lightweight spackle usually has microbaloons (tiny glass bubbles) in it and it is very light."

Thanks for the info.
I really appreciate it.

newbiepilot

What did you mean by this then:

"Lightweight spackle usually has microbaloons (tiny glass bubbles) in it and it is very light. "

newbiepilot

Woops, I posted the same question twice. Sorry about that. So can Microballoons be used for joining two parts together, for filling and for some repair.
Thanks for the info.
I really appreciate it.

davidfee

Microballoons are just a dry filler material... they can be added to virtually any substrate. You can add them to polyester, epoxy, paint, regular wood glue... anything you want. They serve to make the resin/paint/glue more "thick" so it will stay in place. They also fill the substrate with air... the microballoons are tiny glass bubbles... so the thickened material ends up lighter. Because they are glass bubbles filled with air, they also make the cured/dried substrate easier to sand.

Microballoons and epoxy can be used to fill gaps, make fillets, bond composite panels... etc.

Microballoons and some type of water-based latex makes "lightweight spackle."
[link=http://www.custombuildingproducts.com/onlyproducts/patching/inter%20exter%20patch%20n%20paint%20ls.htm]See here for lightweight spackle.[/link]

-David

mattsimonton

alrighty

What is the weight difference between convenional covering and fiberglass
I was contemplating on glassing my delta vortex
I plan on putting a .91 in it so I really don't know weight would factor as much

but what is the price difference

and finally

does the same skill apply to sanding and filling glass bodys for cars(full scale)

Matt

Mike James

mateo,

I wrote to Top Flite and asked them what the weight of their applied coatings was. (without the backing material) and they said "1.8 oz./sq.yd." for the opaque colors... slightly less for transparent. You can glass a plane and match this. But... you still have to add primer and paint. (and if you're so inclined, a clear coat) A glass finish will be heavier, but obviously "better", in terms of stability, longevity, and, if you're good, realism.

The cost will be higher, for the same reason. If you buy resin by the gallon, (say, West Systems, at about $90/gal) and glass cloth in bulk, you can glass a plane for less money than Monokote. But again, you'll have to add primer, paint, and optional clear coat. Then it'll cost a little more. (But, if the price increases of these products keeps going the way it is now, it'll soon be cheaper to use composites than film covering!)

And about the finishing...
Fiberglass is fiberglass... So yes, the same skills will yield the same results. Many of us here depend on the local "body man" to do some of these tasks.

I like both methods. I wouldn't bother to glass and paint a "knock around" .40-size aerobat, but I glass ALL of my "serious" projects.

rglawhead

My Feedback: (34)

I 've just finished my first attempt at fiberglassing a model. It was a TF FW 190 D9. I used Zpoxy and .75 oz weave. It was really a lot of fun, but messy. My question concerns the amount of sanding required, ie. what is the endpoint. According to the Master (Dave Platt), you can't sand too much. I used a light finishing epoxy coat. After several swipes with a square of Nelson's 80 grit sandpaper, it appears that I have sanded away most of the fiberglass weave. I tried to sand off the bumps and gloss of the finish, thinking that it doesn't really matter if I remove most of the fiberglass. The glass is not there to provide strength, but merely to provide a smooth substrate for the paint. Right? If that is right, why don't we just seal the balsa wood and paint over it? Anyway, do I need to recoat the plane? I plan to use "Duplicolor" high build primer/filler, so I don't think I need to recoat the plane just for paint adherence. Help.

kahn41

My Feedback: (4)

I beleive the glass is the strength, glass with the resin does not break very easy, just the resin does... What I use is minwax water base poly with glass. 6 coats took less time to apply than than 2 coats of resin. WB poly dries in about 10 min and a wing took me no time at all. The last thing you want to do is sand into the glass

saramos

rg, 80 grit is too coarse. I use west systems and Duplicolor high build primer for filling the weave. I lay the glass down, brush on the epoxy with a disposable brush, squeegee off excess with those fake credit cards you get in the mail and then blot with toilet paper.
Once cured, I spray a coat of high build primer and then wet sand with 360 grit back to the top of the epoxy (don't sand too much or you can sand through the epoxy). I repeat the prime/sand process until the surface is smooth. Be sure to let the primer fully dry between coats (and especially on the last coat) or the primer will continue to dry and shrink and the weave will show again. Now the surface is ready for surface detailing and/or for a final (non high build) primer coat before painting.

Scott

Campy

My Feedback: (1)

You may also want to consider the polyurethane method of glassing.

MOST people glass a plane to provide a stable, smooth surface for painting,
NOT for strength (that should be done inside the airframe ).

The poly method has about 60% of the hardness and strength of a resin
job, but only 1/2 the weight , the sanding is VERY EASY (you do have to be
careful you do not sand through the cloth ), AND THERE ARE NO FUMES.

Clean up is soap and water.

I have done a couple of 40 - 60 size planes using the poly method and they
have been several ounces lighter than they would have been using resin.

wkevinm

Glassing a fuse or other surface is really quite simple and if done right does not call for a lot of sanding.

First of all make sure the surface you are covering is as well prepared as it would be for a good plastic film covering job.

I use a light cloth .5oz or .75 oz. Cut the cloth using a roller type cutter. Spread the cloth out evenly on the part and then pour a little laminating epoxy... (prefered over polyester) down the center of the piece being covered. Take an old credit card, hotel card or the like and spread from the center out. For compount curves use an acid brush or similar.

Now when you are done spreading the epoxy as thin as possible take a roll of toilet tissue .... this is a very important step......and roll over the cloth and epoxy soaking up as much epoxy as possible. There is little strength in epoxy but lots of weight, strength is in the cloth. if the cloth is not wrinkeld and overlaps are done with care this is the step that minimizes sanding.

When done this step let cure, next lightly sand with wet paper about 300 grit and take any high points off, next prime with a good high fill primer (I use Klasskote), grey for dark surfaces, white for light final colour). Now is where the sanding takes place. Use a good wet paper with a stiff foam sanding block along with a spray bottle and sand, reprime, sand, reprime. after 2 or three coats you should now have the low spots filled (providing you started with a good surface to begin with).

Now paint with a good quality paint, I prefer epoxy (Klasskote).

Total weight.....probably more than monocote or other plastic films when you first do it, after you get good at it, I think the weight difference will be negligible, but you have a good surface, easy to clean and stronger and more durable than a film surface. The time to glass and paint as opposed to covering... no comparison, glassing and painting will take a bunch of time, but the results can be worth it.

The key is to be stingy with the epoxy. I use West System and now East Systems (similar stuff less money), available at boat building stores., along with fiberglass materials at a fraction the cost a hobby shop will charge.

Other things to consider;
... mix balloons with primer to make an easy to sand filler
... store mixed epoxy or epoxy paint in a freezer it will keep for weeks
... warm the epoxy slighly with a heat gun to lower viscosity if necessary when wicking up via toilet tissue or other absorbent
... use a dark primer to get rid of flaws, since they show up better. (use a light coloured primer for light coloured final coats.
... when cutting glass cloth, spread out on a newspaper. The newspaper allows easier cutting and transfer of the cloth to the part being glassed.
... don't thin epoxy, use a low viscosity epoxy such as East or West or others made for laminating with light cloth... not usually found at a hobby store, most (not all) seem to cater to ARFs not for real modelers any more.


Kevin M

skylarkmk1

newbie,

Spackle, both regular and lightwieght are more commonly used to cover the drywall tape and screw/nail divots in drywall/sheetrock used in the walls of houses. Regular spackle has plaster (heavy) and the lightwieght has the micro ballons. You can find the lightwieght stuff in little plastic tubs in any store that carries building supplies (Big Box, Hardware, Lumberyard) and you will swear they are empty when you pick them up.

HighPlains

My Feedback: (1)

Wow, a lot of different techniques and takes on a rather simple procedure.

So one more won't hurt. I built dozens and dozens of Formula One aircraft with the following methods. Weight buildup was always critical, as well as strength. My planes were usually 3-5 oz under the minimum 5 lb weight, and since they could take a 40 g load, very strong.

Sanding - 50% of the sanding is to bare wood. Rough sand with 100 grit, finish sanding with 180. No need to use any finer paper. Get as smooth a surface as you can, and avoid sanding flat spots on the wing. Take your time and get it right. When finished, wipe clean with a soft cloth to remove all sanding dust.

Glassing - Buy a good pair of scissors for cutting fabric. Mark them for cutting glass only, never cut paper or anything else with them. Cut the glass with an inch of overhang and lay on the surface to be covered. On wings start on the bottom surface first. Thin tails may need both sides (top and bottom) covered at the same time to avoid warping. Use the back side of your hand to smooth out the glass so no wrinkles are left. Now you are ready to apply resin.

I use polyester resin. Yes it smells like hell, but nothing gives as hard and stiff of a finish while not building up weight. For a wing panel, it takes less than an oz, but mix enough that you won't run out. Pour a small amount of resin into the middle of the wing panel or other surface. With an old credit card, start working the pool of resin out in all directions from where you start. This prevents any wrinkles and pulls all threads down. Always work out from the starting point in the same direction. Add resin as required. Put the resin on full strength, and squeegee out as dry as you can with the credit card. When you have reached all the edges, put it aside to cure. After an hour or two, use a piece of 320 paper to sand the edges to cut off the excess glass. You are then ready to do the next panel (typically the top side of the same wing panel). This one you will over lap the leading edge onto the lower surface, so the cut needs to be fairly close on the leading edge. Again repeat the process as already described, except for the leading edge overlap.

Important - The hardener is dangerous, and will cause blindness if you get it in an eye, so be careful and do not leave it lying around. Use about 6-10 drops per oz. You do not want it to kick off too soon, on warm days use the lower amount. Also, the glues that it will be exposed to on the surface that is being glassed can be white glue, model airplane cement, CA. On many epoxies, polyester resin will not set up, so if in doubt a thin barrier layer of white glue can be used.

After you have completely glassed the entire wing or fuselage/tail etc., it is time to apply a second coat of resin to all the surfaces. After this has cured for a day, then it can be lightly wet sanded, just enough to scuff the resin. Use 320 paper or 400 for the scuffing. For a really good finish, I usually apply a third coat of resin, and then spend a lot of time wet sanding with a 3M sanding block. Again, with 320 paper, a lot of water, and careful sanding with a rotating motion of the sanding block. Keep a pan of water, keep dipping the sanding block in it, and use a roll of paper towels to wipe down the surface that you are sanding so you can examine what is happening. You will notice that the surface of the wing starts off shiny all over, but as you sand, it will start having a dull surface. Well, the shiny areas are the low spots, and your goal is to eliminate most of the shiny area. Typically once you have about 75-80% of the surface dull, you are ready to hit the primer. Any areas where you have sanded through the glass will need to be sealed with a paper towel and wipe of thin CA. But if your initial sanding before glassing was good, there shouldn't be any.

Primer and paint - Most of the first coat will be sanded off. It should fill the few shiny spots left in resin, and you are ready for the final coat of primer. This one is not a heavy coat, just one to bring the color of the surface to an even tone of color. With a final light wet sanding, you are ready for color. If the color coats cover well, just go for what ever. Other wise, a color like yellow, might do better with a light coat of white for a base. With a good base, it takes much less paint on top to look good. Also, since most people will only see the top of the airplane, use less paint on the bottom to save weight. If you do solid colors without fades or metallic, you can wet sand the entire model with 600 grit to eliminate ridges from paint transitions and then shoot clear coat. If you have fades or metallic, you have to shoot the clear coat on, and then lightly sand it down to eliminate the ridges, and shoot a second coat of clear.

bentwings

And more...
I use the really light weight spackel. I thin it out to maybe tomato soup. I then lightly dampen the wood be it balsa, ply or whatever with a damp sponge. This opens the wood grain and allows th spackel stick better. Then I take the spackel by the hand full and simply rub it on. Yeah I use a lot of it and make a mess sanding but it goes away fast with 60 or 80 grit. It's cheap stuff at about $4-5 a tub about a quart size. by the time I'm done thinning it I probably have 1/2 again the volume. I force drie it if I'm in a hurry otherwise let dry naturally overnight. the 60 grit really cuts it down fast. I use just the weight of the sanding block maybe just a little more and go right to the wood on the high spots. If there is an excessive high or low sopt I'm not beyond cutting it out and replacing it or at least fixingit with structure. Yes it's a pain but i hat it when a spckel filled spot cracks out or cracks al around. Spackel is just to fill n minor spots.

The same with bondo even the light weight stuff. By the time I get to any filling of the fiber glass I'm down to using a small amount of spot putty or 2 coats of primer.

Some of the light weight planes I've done have been painted right after the first coat of epoxy and glass leaving the weave showing. I rarely use more than one thin coat of paint as paint can add a rediculous amount of weight especially if to add in the pre-finishing required. Glass , expoxy, filler and primer.

I try to build the planes straight and true before finishing and try not to have anything to cover up or hide.

RabC

I dont really like the sounds of sanding the wing surface especially when youve spent lots of time getting the profile spot on,you could never sand the profile to be 100% accurate.

jollyroger

My Feedback: (6)

I'm building a glider with an obeichi covered foam wing. There were 5 wing sections to glue together and then cover the wing joints with glass and epoxy. Now what I plan to do is clearcoat the wing instead of painting it. The problem is there is still quite a bit of weave to fill after sanding all the high spots and excess epoxy away.
Should I continue to fill the weave with finish cure epoxy or find something else, but it needs to be a clear filler so as not to visible after clearcoting.
I am using West Systems epoxies and also have their micro light filler, but it seems that it would show up under clear.
Any suggestions?