Fiberglass Question  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       



All Forums >> RC Airplanes >> Composites Fabrication And Repair >> Fiberglass Question Page: [1]

Login
Message << Older Topic   Newer Topic >>
Fiberglass Question - 1/4/2008 3:12:01 AM   
mshick


 

Posts: 139
Joined: 10/18/2006
From: , SC, USA
Status: offline 		Hey Guys,
Wanting to glass a kit built plane. I was thinking some 3oz glass and West Systems which I have used for years. Anyway as you know some wings are built up and completly sheeted and some are built up and partially sheeted. Can you glass a wing that is only partially sheeted and the rest is ribs with caps on them? My guess is I should stick with a kit that has fully sheeted wings.

Thanks
Mike
       Post #: 1

RE: Fiberglass Question - 1/4/2008 3:27:02 AM   
jeffk464


 

Posts: 1240
Joined: 10/31/2004
From: cerritos, CA, USA
Status: offline 		3 oz cloth will make the plane way to heavy, the standard seems to be 3/4oz cloth for fully sheeted surfaces. I would go with fully sheeted and the 3/4 oz cloth, then you have to decide between epoxy and water based polyurathane.

(in reply to mshick)
       Post #: 2

RE: Fiberglass Question - 1/4/2008 2:42:20 PM   
Campy



Posts: 3379
Joined: 1/2/2002
From: Baltic, CT, USA
Status: offline 		3 oz cloth is too heavy. Use 1/2 oz or 3/4 oz fiberglass cloth. It is your choice as to use resin or waterbase polyurethane. The resin is harder, but heavier. The WB poly has about 60% of the strength of resin, but only 1/2 the weight. In either case, if you need the strength, do it with/in the airframe, not the finish.

Glassing needs to be applied over a fully sheeted surface.

Here is a basic "How To" for glassing with waterbase polyurethane. The same principles will also apply to using resin.

Glassing with Water Base Polyurethane


1. Sand the model with 220 grit and remove any highs/lows you may find.
Fill as needed with lightweight filler and sand.

2. Give the wood 1 thin - medium coat of wood sealer. I use the
commercial stuff. What this does is twofold - it stops the balsa
from soaking up too much of the poly and at the same time protects
the balsa from the water in the polyurethane.

3. When dry, sand lightly with 220 to remove the "fuzzies".

4. Some people say to apply a light coat of 3M #77 adhesive to the
wood at this point. I have found that this is more trouble than it
is worth since if you have a wrinkle, the complete piece of fiberglass
has to be removed to straighten it out.

I prefer to lay the fiberglass cloth on the part/area to be covered and
smooth it out using a SOFT brush. Brush FROM THE CENTER TOWARDS THE
EDGES. The static electricity usually holds it in place. I normally
use 1/2 oz (.5 oz) or 3/4 oz (.75 oz) fiberglass cloth.

5. Using WATER BASE polyurethane and a FOAM brush, start at the center
and brush towards the edges of the fiberglass. All you want to do is
stick the fiberglass to the balsa, so excessive amounts are not needed.
Any additional pieces of fiberglass should overlap each other about
1/2 - 3/4 inches.

Let this dry. DO NOT SAND !!

Brush on another coat of polyurethane. This coat can be a little heavier.

Let this coat dry. DO NOT SAND !!


6. Mix up some polyurethane and microballoons. I use 1 part
microballoons to about 5 parts polyurethane. This will be on the thick
side.

Brush on a medium coat of this mixture and let dry.

7. Wet sand this with 220 or 320 grit paper. BE CAREFUL, AS YOU CAN
VERY EASILY SAND RIGHT THROUGH THE FIBERGLASS.

8. Check the fiberglass carefully to insure the weave is filled. If
the weave is not completely filled, repeat step 6 and 7.

9. SPRAY a coat of water base polyurethane on the plane and let dry.
DO NOT SAND !!

10. Spray a THIN coat of primer on the plane. When this is COMPLETELY
dry, block wet sand with 220 or 320 grit as much of the plane as
possible to highlight any highs/lows you may have missed during your
sanding/prep. The areas that can not be block sanded, CAREFULLY sand
by hand. (TIP: CA some of the wife's/girlfriends fingernail file boards
together. Wrap the sandpaper around them so you can block sand in tight
areas. The CA helps prevent the boards from disintergrating in the water)
Fill any low areas with a lightweight filler and sand when dry.

Apply a THIN coat of polyurethane to these areas.

When the poly is dry, repeat this step until you are satisfied that all
the highs/lows are removed.

11. SPRAY a thin coat of polyurethane on the plane. When dry, spray
the primer.

12. When the primer is dry, you can apply your rivets, panel lines and
other detailing desired.

13. Now you can spray your paint.

(in reply to jeffk464)
       Post #: 3

RE: Fiberglass Question - 1/4/2008 8:51:43 PM   
mshick


 

Posts: 139
Joined: 10/18/2006
From: , SC, USA
Status: offline 		Yes I ment to say 3/4 oz. Sorry about that. Great info guys. I appreciate the advise. My next step will be to pick out a kit to start with. I love working with glass so this should be fun. Thanks agaiin!!

Mike

(in reply to Campy)
       Post #: 4

RE: Fiberglass Question - 1/4/2008 9:57:46 PM   
Atlanta 60



Posts: 1035
Joined: 2/15/2003
From: Cartersville, GA, USA
Status: offline 		Campy...Great Stuff there!! Thanks Very Much!!

Chuck

_____________________________

"A Superior Pilot uses his Superior Judgment to avoid using his Superior Skills." - astronaut Frank Borman

(in reply to Campy)
       Post #: 5

RE: Fiberglass Question - 1/5/2008 1:23:42 AM   
j.duncker



Posts: 1137
Joined: 6/22/2004
From: Where I park the RV, AK, USA
Status: offline 		There is a way to glass an open structure.

Cover it with tissue first water shrink and dope. One coat is fine.

Then glass. I have never used West systems to glass an aircraft, just make sure that you have the correct type of resin if you intend to apply multiple coats.

_____________________________

The dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible.

(in reply to Atlanta 60)
       Post #: 6

Page:   [1]
All Forums >> RC Airplanes >> Composites Fabrication And Repair >> Fiberglass Question
Page: [1]





Jump to:


Google 



Search | Marketplace | Event Calendar | Local Clubs | Magazine | Product Ratings | New Products | Discussion Forums

Photo Gallery | Member Video Posts | RCU Video Gallery | Instructor Search | Field|Track|Marina Search

Advertisers | Hobby Vendor Resources | Rate Manufacturers | Sign In/Sign Up

SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.

Charities we support that also need your help
Yorkie Rescue | Humane Society | ASPCA | Crohn's-Colitis America

Kaango.com Classifieds

0.938RCU1