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Jul 28, 2008, 06:01 PM
that tree ate my plane
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Discussion

monokote over fiberglass


i am building a p-51 mustang and will be using polished aluminum monokote and flat aluminum monokote. the plane is fully sheated and i was thinking of applying a layer of .75 oz glass to it to make a smother finish will there be any ill effects when i apply the monokote
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Jul 28, 2008, 06:39 PM
Registered User
I don't see why you would do that, the Monokote is pretty smooth, I don't see any smoothness benefits of the glass.
Jul 28, 2008, 06:49 PM
that tree ate my plane
rotccapt's Avatar
i figured that the wood grain might show through on a fully sheeted plane. with fiberglass it would be a little bit stronger and also after fill ing and sanding it would be very smooth
Jul 28, 2008, 07:59 PM
Guz
Guz
Gutless wonder
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Practice first

Putting monokote on a smooth surface can be frustrating, i.e. lots of air bubbles.
Jul 28, 2008, 10:12 PM
Registered User
I've had bad experiences trying to monokote over epoxy and/or polyester resins. The adhesive in the monokote let go over time for me.

If you've got course grain to fill use lightweight spackle and then sand if off, that will fill all the grain. You can probably find it at your local hardware store in a tub that feels empty/light. If not you can buy the expensive hobby grade stuff like this http://www3.towerhobbies.com/cgi-bin/wti0093p?&C=RMC. Don't worry about the cost... a little goes a long way.
Jul 29, 2008, 07:17 AM
Registered User
I think you'll find MonoKote to be very good at covering balsa and hiding grain that has been finished sanded down to 320 grit paper. I've had excellent aheasion with Monokote over fiberglass cowls laid up with 5:1 epoxy finishing/lay-up resins; the fiberglass parts/areas also need to be finished sanded down to 320 grit.

MonoKote over fiberglass (even balsa sheet) invites traped air. For your Mustang consider covering to mimic all the aluminum panels as seperate pieces of covering, as smaller pieces are easier to work out air bubbles. Start from the center of a panel and iron down in a circular motion. Use a covering sock on the iron.

20 years ago I covered my DC-3 with scuffed chrome MonoKote, with panel pieces over fine sanded balsa and it is very hard to see any balsa grain even now.
Jul 29, 2008, 08:49 AM
that tree ate my plane
rotccapt's Avatar
david did you have problems with glow goo getting under the panels of mono and lifith them? i may have to do that i was thinking of using flight metal but i think that my plane will be too heavy with it i ab building a 1/7 scale top flite mustang and powering it with a saito 125 and a scale muffler
Jul 29, 2008, 09:44 AM
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Quote:
Originally Posted by rotccapt
david did you have problems with glow goo getting under the panels of mono and lifith them? i may have to do that i was thinking of using flight metal but i think that my plane will be too heavy with it i ab building a 1/7 scale top flite mustang and powering it with a saito 125 and a scale muffler
No, but I took measures to prevent that.

1. First apply an epoxy finishing resin to fuel exposed wood in the engine area. I'll then apply a colored Dope over that extending into the area to be covered in film. Dope and Balsarite provide extra adhesion.

2. As a final prevention, I'll run a line of thin CA where the covering ends at the painted areas.

If you happen to have a copy of Model Airplane News from 02/1989, you can see how my DC-3 turned out.

Flight metal requires a lot of work and I'm lazy. MonoKote is much easier and lighter.

Wood prep is everything for MonoKote and the wood must be oil free and completly free of any dust (compressed air is the only way to remove dust). If MonoKote sticks to dust it will lift later and can't be re-sealed.

MonoKote requires good heat and pressure to adhere. A bare shoe won't work and a TopFlight Sock isn't a whole lot better. I prefer to sand off the nonstick shoe coating and stick a piece of white craft felt to the shoe with silicone adhesive. This gives the ability to apply higher even pressure and avoid any scratches. Felt is easy and cheap to replace as it wears and turns brown from the heat.

I use a Trim seal tool set on high to seal seam overlaps ... Enough time and just enough pressure to see the adhesive oooze from the seam. Clean up with lacquer thinner.

Ask a simple question and what do ya git.......
Jul 29, 2008, 12:09 PM
that tree ate my plane
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how much overlap did you have 1/8" or was it less also did you shingle the panels aka start at the back and work forward
Jul 29, 2008, 04:03 PM
Registered User
The average overlap was 3/32" and yes, for the fuselage, back to front. On the wing , stab & rudder, trailing edge to leading edge with the final piece along the leading edge.
Last edited by David A Ramsey; Jul 29, 2008 at 04:09 PM.
Jul 29, 2008, 04:40 PM
that tree ate my plane
rotccapt's Avatar
do you have any pics of your dc-3 that you could share i like this idea and would like to see what it looks like then again i could just try it with some scrap. thanks for the info
Jul 29, 2008, 05:00 PM
Registered User
Rats! I was afraid you might ask. I was gonna offer, but she's been hanging for a couple of years and needs a dusting. I could scan some old color photos but I think you might like some close-ups too. I'll try my best to post tomorrow before noon.
Jul 30, 2008, 02:43 PM
Registered User

Close-ups


I hope these additional photos help.

To skuff: A half roll of Chrome MonoKote is laid out on a flat, clean surface. I used a 4' x 4' sheet of acrylic with the masking paper still attached. The whole half sheet is scuffed in one direction. Any dust, or tiny bits and pieces between the flat base surface and MonoKote will show up during scuffing. I originally used a new piece of gray (fine) Scotch Brite which is available from automotive finishing stores.
Note: a new gray pad, if rubbed too hard, will deeply score the covering to the point where it can be torn on the deep cuts. To make the pad a bit softer, use it to scrub pots and pans for a couple of days. Fine steel wool should be avoided as, in use, it leaves bits of wire all over.
Over scuffing leaves a flat dull finish. Usually about 3 light passes in one direction looks about right. Try it on some small pieces to see the possible effects.
Using a plastic model kit; brushed chrome MonoKote pieces are scaled and cut to follow the panels from the plastic model.

The photo of my covering irons show 2 irons with felt pads. 1 is worn and discolored from use and the higher heat required to get throught the added felt thickness; the other one has a new felt pad.
To add a felt pad, pick an iron that has a used shoe with the non-stick coating worn or scratched. Sand off all the bottom coating with 80 grit paper. Next apply any silicone sealant in a smooth layer on the shoe base and press an over size piece of craft felt on the shoe. Turn the iron on and set to high tempreture. After about 10-15 minutes the silicone will be cured and the excess felt trimmed. Works great for ironing film to sheeted surfaces and provides a nice cushion for firm, even pressure and no scratches. Generally one felt pad will do an average model. This DC-3 took 2 pads.
Jul 30, 2008, 03:53 PM
that tree ate my plane
rotccapt's Avatar
that is a very nice looking model thanks for posting the pics they help a lot i may have to do that.


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