JollyPopper

My Feedback: (6)

OK, guys and gals, I have been reading from time to time about covering an airplane in fiberglass cloth and painting as opposed to covering with Monokote, Ultracote, etc. However, I have a couple of questions about the technique. First, when butting two pieces of cloth together, how do you folks avoid an unsightly seam? Do the sheets not overlap--just butt them together and fill with epoxy, resin, whatever the choice is, or do you cut the sheets somehow so that there is no butting/overlapping? That would, on the surface of it, appear to be damned near impossible. Secondly, how do you folks fiberglass over open bays in wings and such? Do you fully sheet the wing first? Seems that would defeat one of the reasons to fiberglass in the first place, that being that it is lighter weight than shrink covering. I'm sure there will be more questions as I think about this, but that will do for starters. And please don't tell me to do a search. Thanks in advance for your answers, folks.
Max

Scar

My Feedback: (3)

You only 'glas over sheeted (or planked) surfaces. No open bays. The object is strength.

Use a large enough section to cover an entire top or bottom of a wing, for instance, and let the seam happen at the edge. Some filler at that location will help the appearance.

I have never heard anyone claim that 'glas is used to achieve lower weight than iron-on film. The advantages include a paintable surface, strong enough to resist dings & hangar rash, added structural strength, and repairability. I may have missed some. Did I mention the strength improvement?

Good luck,
Dave Olson

Kelsey_B

Max,

I just glassed my first plane, and I didn't know a thing about it. Try to minimze overlaps, but there will be some. Just sand to edge of the top pc to feather it. Similar to a drywall joint. Its there, you just hide it.

There are many methods of glassing. I reviewed Lukes Royal corsair thread, and he explains his very easy method.

Keith

Campy

My Feedback: (1)

First, you can only glass over sheeted (or planked ) areas.

2nd. Glassing provides additional strength to the plane AT A COST - WEIGHT

3rd. You can do a glassing job that will be relatively lite weight. Monokote weighs in at about .2 oz per square foot - glassing with polyurethane SHOULD come in around .3 oz per square foot. Once you add paint you will be around (depending on the type of paint and how heavy you apply it ) .4 oz per square foot.

See the attachment for how to glass with polyurethane.

Scar

My Feedback: (3)

After reading the original post again, I'm wondering if JollyPopper is confusing the use of a fiberglas fuselage with the practice of 'glassing a sheeted or planked structure.

A fiberglas fuselage is usually lighter than the corresponding former-built balsa/ply fuselage, covered with film or fabric. There are tradeoffs, in building technique.

A balsa fuselage or sheeted wing, covered in fiberglas and painted, would seldom be lighter than the same structure covered in film.

Just a thought,
Dave Olson

JollyPopper

My Feedback: (6)

Dave,
I wasn't confusing a fiberglass fuse with covering with fiberglass. I read here, on RCU somewhere, that glassing would produce a lighter finish than shrink film. I didn't understand that at the time, but I do understand the structural strength gain. I also like the idea of painting, especially since there are virtually no limits to the colors you can get in automotive paints. And there is always the chance that you can pick up some colors that were mixed incorrectly, or that someone else ordered and didn't pick up, at some ridiculously low price.

So, as I understand it now, the two options on a wing (open bays) are 1) completely sheet and then glass and paint the wing, or 2) cover the wing with heat shrink film and get paint to match the film color. Are there other options? And wouldn't sheeting and glassing a wing make it terribly heavy?

Thanks for the input, guys. Keep it coming. I'm gonna do this and any ideas anyone has will help.

Max

kdheath

Phil Granderson uses an interesting approach to cover/paint. He uses nitrate dope to cover the entire airframe (open areas and all) with .2 oz carbon fiber veil. He cuts the veil away at the open spots and covers over the rib bays with silkspan. He shoots a few coats of Brodak butyrate clear dope to seal everything. Then he sprays a coat of dope nixed with commercial talc from Tapp Plastics as a filler. Sand, and shoot with the auto color and clear coat. He says he adds about 8 ounces to a 700 sq inch plane for a front row finish.


The CF veil/dope matrix has most of the advantages of fiberglass and weighs less. PTG had an article in MA this year or late last. This is an excellent technique and easy to do, as an alternate to glass.

rc-sport

My Feedback: (12)

Have you ever worked with dope? COUGH COUGH HACK WEEZE Nasty stuff

Scar

My Feedback: (3)

Hi Max,

Okay, I'm on the same page with you now.

We're in agreement that 'glas over sheeting is not the lighest treatment. The attraction there is in the durable, paintable surface, and added structural strength.

You, on the other hand, are looking for a lightweight surface, applicable over open bays, and with color options. I don't think anyone has mentioned Koverall or Solartex, yet. Both fabrics can be obtained unpainted, can be adhered with paint-on heat-sensitive adhesive, and are lighter than sheeting and glassing. Unlike fiberglas, these coverings can be applied over open bays and shrunk to fit. While heavier than the colored mylar iron-on films, they offer the option to paint in your choice of color. You might want to check with Sig or Balsa USA for details on these.

Best Wishes,
Dave Olson