Bob Smith Industries 900x250 v2

Create a perfect fiberglass finish

Create a perfect fiberglass finish

Here’s another how-to from veteran builder Rick Michelena. Enjoy!

Do you have the desire to build a warbird or other scale project but desire something more than an iron-on finish? Are you unsure of the steps required in the process of finishing a radio-controlled airplane in fiberglass and paint? This article will give you the knowledge required to finish any project. In fact, by following these steps, your models will look better than 95% of the models appearing at your local club.

Before we begin, I would like to mention that I do not compete in Top Gun events nor spend the necessary time required to build these master- pieces. I build my models to fly and to last. As those who know me will attest, my models have each accumulated thousands of flights over 25+ years in service. My motto is simple: No hangar queens!

However, if you desire to learn how to fiberglass and paint, these tips will help you go the “extra mile.” With that said, let’s discuss the necessary steps involved in producing an excellent finish on your next project.

This is the wing of my giant scale F8F Bearcat. It is a foam core covered in 3/32″ balsa skins and has been sanded with #100 sandpaper.

Lightweight spackling is the secret for creating a perfectly level finish. It is available at both Lowes and Home Depot. It is lightweight and will fill every imperfection in your balsa skins.

After I blow all the sanding dust off the wing, I use a spray bottle and water to slightly dampen the balsa skin. With a plastic “Bondo” spreader, I spread the spackling all over the wing area. If it becomes dry, mist some water on it to smooth it out. I allow this to dry overnight.

I do the same procedure with all the flight controls.

This is the horizontal stabilizer. Please notice the darker area where I used fiberglass tape to attach it to the fuselage.

I then skimmed the lightweight spackling over all the surface. This is an important step in leveling any surface and is an essential step in paint preparation.

A Black & Decker Mouse sander will save both time and energy. I begin with #100 paper and use a block-sanding motion (sanding back and forth in an “X” pattern) to level the surface where the fiberglass cloth will lie.

Remove the majority of the lightweight spackling, and this surface is now perfectly level in preparation for the next procedure, which is fiberglassing. Don’t let this next step scare you. The process is easier than you think.


Here are the simple items needed to produce a fiber-glass finish that will last for many years. You will need the following: 3/4 ounce fiber-glass cloth, 90% isopropyl alcohol, Z-Poxy finishing resin, mixing cups, stir stick, scissors, and sponges cut in small squares.  We’ll continue with the rest of this project next week — stay tuned!


Updated: November 8, 2015 — November 8, 2015


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  1. Hey, let’s get on with this, I am using this procedure to restore my full scale Pipeer Cub. If it is as good as you say, then I am a chinch for the best finish award at Oshkosh this year. thanks. d

  2. In spreading the resin I have had great success using playing cards which can scrape the excess resin out of one spot to spread to a spot that needs it,no waist ! I did an 85″P51 wing with 4 oz’s (less flying surfaces) that’s top and bottom,don’t let it soak in.Use one oz at a time you only need enough to make it stick.Check out my P51 “RED DOG XII” on youtube. It took 2nd place at scale squadron for Best prop war bird.

  3. Is a Piper cub Fabric covered? If so it wont work.

  4. Is it next week yet?

  5. Did you graduate Roxborough High School in 1972? I did.

  6. you can wear you finger tips out doing this work but all the rubbing will provide a finish like not plastic kote will provide no seams to get fuel soaked or peel off. Beware it is time consuming but if it yours it is worth it!

  7. Very helpful,I’m learning a lot that I didn’t know,I glasses my cub 4 years ago fly great but the glass resin is not getting hard,I used 2. Part epoxy resin?

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