RC Gliders, Sailplanes and Slope Soaring Discuss rc gliders,rc sailplanes and slope soaring in this forum. Thermaling techniques, airfoils, tips, etc

"Glassing"

Reply

Old 01-22-2005, 06:32 PM
  #1  
tunabiker
Member
Thread Starter
 
Join Date: Sep 2003
Location: Del Mar, CA
Posts: 41
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default "Glassing"

I hope this is easy! I'm building an Oly II and want to reinforce the tail section. My desire is to fiberglass about 8" underneath the Stabilizer. The Glass resin I have does not cure around either Epoxy or CA. I figure I can use thinned epoxy to bind the fiberglass cloth, but don't know how to thin it. I tried alcohol, but it wouldn't cure.

What proportions should I use?
Does the container I use affect curing (like a plastic cup)?
Is 5 min. better than 30 min. epoxy?

Thanks for any help!

Tunabiker
tunabiker is offline  
Reply With Quote
Old 01-24-2005, 04:39 PM
  #2  
isoar
Member
My Feedback: (1)
 
Join Date: Oct 2004
Location: Sage, AZ
Posts: 34
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: "Glassing"

Oh Please don't.

If built to the plan and built well, the tail boom is plenty strong. It has spruce longerons inside the balsa box fusilage as well as triangle stock in the corners. I've built/flown several and never broke one there in many crashes. I mean I've demolished the nose section in strait in dives, but the boom always held.

Extra weight in the tail means 3 or 4 times that much extra weight in the nose to balance it.

That's my 2 cents for what it's worth.

Why do you feel glassing is needed?
isoar is offline  
Reply With Quote
Old 01-24-2005, 04:52 PM
  #3  
isoar
Member
My Feedback: (1)
 
Join Date: Oct 2004
Location: Sage, AZ
Posts: 34
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: "Glassing"

Sorry to be a wet blanket on your above idea as much of the the fun of this hobby is experamintation.

As to your core question, I'd use 30 minutes which gives you more time to wet out the cloth thorughly and blot our the excess epoxy with paper towls. (The real steanth is in the glass cloth, not the expoxy.) To get the epoxy a little thinner like you said you wanted it, you can heat the expoxy slightly by putting the bottles in hot water or hitting the mixture briefly with a heat gun. That's an alternative to adding a liquid thinner (which I've never done so I'll be listening to other replys). Epoxy "goes off" faster when mixed in a cup than when allowed to spread out like on a piece of waxed paper, but either will work fine.
isoar is offline  
Reply With Quote
Old 01-24-2005, 07:18 PM
  #4  
tunabiker
Member
Thread Starter
 
Join Date: Sep 2003
Location: Del Mar, CA
Posts: 41
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: "Glassing"

Ouch! I went ahead and used light glass cloth and held it in place with some MMM 77 spray, then used a LIGHT layer of slow cure epoxy (thinned with a couple drops of alcohol) which seemed to work fine. I surely hear your concern about the weight and, maybe, I have overdone it. I hope not. I have kept the weight pretty well down, and I did scrape this quite thin, so I think I'll be ok. I have been much more concerned with strength than weight on this plane as it seems to fly quite well. My piloting skills are not great, so I managed to cartwheel the previous model. Wings came out fine, but the empennage split (horizontally) underneath the stab in the tail section...hence, I felt a layer of fiberglass would add some desired "accident compensation". Thanks for your advice. I probably jumped a little bit early. Still, I'm hopeful and will give you a holler-back after I've flown the plane. It will still be a little bit!
Bill
tunabiker is offline  
Reply With Quote
Old 01-24-2005, 07:57 PM
  #5  
BMatthews
 
BMatthews's Avatar
 
Join Date: Oct 2002
Location: Chilliwack, BC, CANADA
Posts: 12,337
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: "Glassing"

Using a hair dry set on high makes epoxy run like water. Try it. It thickens up when it cools and the heat accelerates the cure so definetly start with 30 minute stuff at least.

There is a proper epoxy laminating resin available. You can probably buy a "model" sized repair pack at the local boating supply outfits. West Systems is one notable brand but there are others. The term "laminating" is the key as it means it's intended for fiberglass applications.

Ditto on the glass cloth being the strong stuff and not the resin. As long as you have enough resin so the cloth looks clear then you have enough. Anything more than that is WEIGHT. Don't try for a smooth glassy finish either. The cloth just floats up in the resin and you end up heavy. Instead use just enough to wet out the cloth to transparent and let cure. Sand the edges and any lumps and brush on a second very thin coat of resin to fill the weave. If painting don't bother with the second coat. Use a scrape of lightweight wall filler to fill the weave instead
BMatthews is online now  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service