Mega Rebel with Monokote

[Crawf56]

Having completed my Mega Rebel, I am moving forward on a project to cover it with Monokote.

Monokote is a heat shrink plastic film, often used on RC aircraft.

The Mega Rebel is a 'different' design, in that it has an exposed structure. The rocket has already had a successful launch.

 

[Crawf56]

The Mega Rebel is available from Rocketarium: https://www.rocketarium.com/Rockets/Mega-Rebel

Here is my Mega Rebel build thread: https://www.rocketryforum.com/threads/mega-rebel-from-arkansas-rocketarium-phase-1.156618/

 

[neil_w]

This should be interesting.

 

[Crawf56]

Here is a link to Monokote: https://www.towerhobbies.com/cgi-bi...&V=TOP&D=Top-Flite-Covering---Iron-On-Plastic

Monokote is an iron-on plastic, made by Top Flite. Sadly, Top Flite is likely being phased out, and is being replaced by UltraCote:
https://www.towerhobbies.com/cgi-bi...A&V=HAN&D=Hangar-9-Covering---Iron-On-Plastic
Both brands are very similar. The same irons and heat settings are used for both.

Generally, you iron on the monokote (or ultracote) at around 250 F. Then, you go back and iron again at around 325 F to get the final shrink & adhesion.

 

[Crawf56]

Since this stuff is a film, you must have a surface to attach each edge. I am starting work on the nosecone of the Mega Rebel. It has 4 "ribs" that interlock with the body. Here is a pic of the upside down nose, during construction.

 

[Crawf56]

So, I start with some cardboard, and trace a shape on the body.

 

[Crawf56]

I will use the blue cardboard as a guide for a balsa cutout. Showing location on the nosecone.

 

[Crawf56]

Thanks for looking in, neil_w.

I measured the CG in my previous thread; I will use that info to help obtain a stable model.

 

[Crawf56]

Need to add some surface to the nose of the Mega Rebel. Using 1/2" x 1/2" balsa. Glued with medium CA, then sanded.

 

[Crawf56]

Next, I added balsa where the launch rod goes through. This is done to provide a surface for the monokote to attach to.

 

[Crawf56]

I confess to a little cheating. I glued balsa in place, then used an extended drill that I got from B&B Specialties.....which they seem to no longer carry.

Could have drilled hole in balsa, then glued in place.

 

[Crawf56]

Nose all sanded.

 

[Funkworks]

... The same irons and heat settings are used for both.

Generally, you iron on the monokote (or ultracote) at around 250 F. Then, you go back and iron again at around 325 F to get the final shrink & adhesion.

If an iron is enough, what do they sell a heat gun for?

 

[aerostadt]

I think this is going to be a lot of work, either lengthwise planking or a master of shrouds.

 

[Crawf56]

If an iron is enough, what do they sell a heat gun for?

To apply monokote, you MUST have an iron. This is needed to attach the monokote at a specific point.

A heat gun is good help, but not required. A heat gun is used after the monokote has been applied, to help remove wrinkles. Since the heat gun acts over a broader area, it produces a larger area of shrinkage. This tends to give monokote (or ultrakote) a better look.

NOTE: I strongly suggest you use a heat gun made for monokote. Heat guns from a typical hardware store tend to be too hot, and can damage the monokote.

 

[Funkworks]

To apply monokote, you MUST have an iron. This is needed to attach the monokote at a specific point.

A heat gun is good help, but not required. A heat gun is used after the monokote has been applied, to help remove wrinkles. Since the heat gun acts over a broader area, it produces a larger area of shrinkage. This tends to give monokote (or ultrakote) a better look.

NOTE: I strongly suggest you use a heat gun made for monokote. Heat guns from a typical hardware store tend to be too hot, and can damage the monokote.

Ok cool. I did buy some Monokote to stripe a 2.1" PML AMRAAM as recommended by their instructions. I was about to buy an iron + heat gun combo, but the store was out of stock. Maybe I'll just get the iron then. And later on, I suppose I could try a regular heat gun, but from 5 feet away, and slowly close in.

 

[mbeels]

The heat gun is more useful for shrinking sections of monokote that span an open bay. Airplanes often have open frame construction, and the heat gun helps shrink those more uniformly and quickly. The heat gun is also useful for applying heat and pulling and stretching monokote to get it to go around compound curves (like a nose cone). The iron is good for activating the heat sensitive adhesive and attaching to solid balsa structure. If you have flat, or cylindrical solid surfaces, just get the iron.

 

[Funkworks]

Alrighty then.

 

[Crawf56]

The heat gun is more useful for shrinking sections of monokote that span an open bay. Airplanes often have open frame construction, and the heat gun helps shrink those more uniformly and quickly. The heat gun is also useful for applying heat and pulling and stretching monokote to get it to go around compound curves (like a nose cone). The iron is good for activating the heat sensitive adhesive and attaching to solid balsa structure. If you have flat, or cylindrical solid surfaces, just get the iron.

Well said.

 

[Crawf56]

Ever forward. Making sure the holes all line up for the launch rod.

 

[Crawf56]

Also make sure the nose is 'interlocked' in the slots on the body. (Where pencil is pointing.)

 

[Crawf56]

Using my blue cardboard cutout to make balsa sections. Using 1/8 inch balsa...….because it seemed about right.

 

[Crawf56]

I cut the balsa a little larger than my guide, so I can sand it to fit.

 

[Crawf56]

The purpose here is to make a lower structure for the nose so the monokote can attach.

After some sanding, an acceptable fit (not perfection).

 

[Crawf56]

With the nose still in position, I clamp the balsa in place. This prevents movement while the epoxy dries.

 

[Crawf56]

And applying 5 minute epoxy. I chose 5 minute because it does not run like 15 minute or 30 minute epoxy. Don't want to permanently glue the nose to the body!

 

[Crawf56]

And here ya go. Note that I only epoxied the upper surface. I will go back with CA.

 

[Crawf56]

Again, slight overhang compared to the body. Will be sanded back.

 

[Crawf56]

Working on the other two lower nose supports.

 

[Crawf56]

I have been using Devcon 5 minute epoxy, which I got from Ace Hardware. Good stuff.