Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > The Doctor is In! > Ask the Doctor
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 10-12-2007, 04:15 PM
F_O_G F_O_G is offline
Too young to be a BAR
 
Join Date: Sep 2007
Location: Montana
Posts: 130
Default Epoxy

is it ok to use elmers white glue in place of epoxy?
Reply With Quote
  #2  
Old 10-12-2007, 04:21 PM
ScaleNut's Avatar
ScaleNut ScaleNut is offline
Craftsman
 
Join Date: Apr 2005
Location: Heart of the South
Posts: 269
Default

yes , atleast on model rockets
Reply With Quote
  #3  
Old 10-12-2007, 04:48 PM
pyrovette20 pyrovette20 is offline
Wile E. Coyote super genius
 
Join Date: Jun 2006
Posts: 28
Default

Why would you want to. I epoxy everything.
Reply With Quote
  #4  
Old 10-12-2007, 05:02 PM
Shreadvector's Avatar
Shreadvector Shreadvector is offline
Launching since 1970.
 
Join Date: Mar 2005
Location: Southern California
Posts: 2,188
Default

Epoxy adds weight because it does not contain water that evaporates.

Heavy rockets can be unbalanced/unstable rockets.

Yellow wood glue is perfect for cardbaord, wood and paper. It will not stick to plastic and metal, but epoxy will.
__________________
-Fred Shecter NAR 20117 (L2)
Southern California Rocket Association, NAR Section 430
Reply With Quote
  #5  
Old 10-12-2007, 06:34 PM
barone's Avatar
barone barone is offline
Master Modeler
 
Join Date: Apr 2005
Location: Bartlett, TN
Posts: 3,352
Send a message via Yahoo to barone
Default

Quote:
Originally Posted by F_O_G
is it ok to use elmers white glue in place of epoxy?

Depends upon what you are bonding. Elmer's white glue isn't very good for plastic to plastic or plastic to wood or plastic to anything. If a plan is specifying epoxy for a construction bond, there is probably a reason for not using the white glue. What is the specific application?
__________________
Don
NAR 53455
"Carpe Diem"
Reply With Quote
  #6  
Old 10-12-2007, 10:12 PM
tfischer tfischer is offline
Craftsman
 
Join Date: Sep 2007
Location: Minneapolis, MN
Posts: 202
Default

Another tidbit is that white glue and yellow glue are essentially the same thing, as far as adhesion is concerned. The difference is that white glue has a much longer "open" or "workability' time then yellow glue. I'm a woodworker, and most woodworkers prefer white glue due to the fact that things can be positioned, etc. rather than immediatly sticking. The final bond is the same strength.

With rockets, many people seem to prefer the yellow glue so that the fin (or whatever) will lock into place much sooner without having to be held forever.

-Tim
Reply With Quote
  #7  
Old 10-13-2007, 09:56 AM
ghrocketman's Avatar
ghrocketman ghrocketman is offline
President, MAYHEM AGITATORS, Inc.
 
Join Date: Jul 2005
Location: Nunya Bizznuss, Michigan
Posts: 13,443
Default

Depends on the rocket power level whether white glue or Titebond will be enough.
As a rule I use Epoxy for fins and engine mounts for ANYTHING that will see "E" power and above.
Most likely overkill, but good insurance for mid-power rockets using engines from E through G.
Needless to say, for hi-power (H and above) epoxy is a must.

For run of the mill A to D power it just adds weight.
__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL
, if you have to ask what is "NORMAL" , you probably aren't !

Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !
Reply With Quote
  #8  
Old 10-14-2007, 01:19 PM
Mach1's Avatar
Mach1 Mach1 is offline
Rocket Junkie
 
Join Date: Aug 2007
Posts: 48
Default

Quote:
Originally Posted by F_O_G
is it ok to use elmers white glue in place of epoxy?


I'd use yellow carpenter's glue in place of the white glue. White glue will work, but the yellow is stronger. The bond of the yellow glue is much stronger than common model rocket materials anyhow.

Most of the time, (unless I have a special situation) the only time I use epoxy in model rockets is to secure the motor mount. A motor mount can be secured in with yellow glue just fine, but you will end up with a "pucker" ring on the outside of the body tube. The yellow glue shrinks when it dries causing the ring to appear.
__________________
Joe Michel
NAR 82797 L2
http://www.geocities.com/jm44316
Reply With Quote
  #9  
Old 10-14-2007, 02:16 PM
ScaleNut's Avatar
ScaleNut ScaleNut is offline
Craftsman
 
Join Date: Apr 2005
Location: Heart of the South
Posts: 269
Default

Quote:
Originally Posted by tfischer
Another tidbit is that white glue and yellow glue are essentially the same thing, as far as adhesion is concerned. The difference is that white glue has a much longer "open" or "workability' time then yellow glue. I'm a woodworker, and most woodworkers prefer white glue due to the fact that things can be positioned, etc. rather than immediatly sticking. The final bond is the same strength.

With rockets, many people seem to prefer the yellow glue so that the fin (or whatever) will lock into place much sooner without having to be held forever.

-Tim


white glue is Polyvinyl acetate

wood glue is Aliphatic Resin

as far as the bond strength titebomnd III runs around 4000 psi and has a longer open time, it's stronger than gorilla glues !
white glue doesn't even enter the ballpark, however for balsawood it's plenty strong.

here's a prety good essay on glues from a woodworker site
http://www.woodcentral.com/russ/russ6.shtml

Last edited by ScaleNut : 10-14-2007 at 06:59 PM.
Reply With Quote
  #10  
Old 10-14-2007, 04:12 PM
tfischer tfischer is offline
Craftsman
 
Join Date: Sep 2007
Location: Minneapolis, MN
Posts: 202
Default

Quote:
Originally Posted by ScaleNut
white glue is Polyvinyl acetate

wood glue is Aliphatic Resin



There's a lot of conflicting information on this on the web, evidently. Some sites say "yellow glue is PVA". Others say it's "Aliphatic Resin". Still others say it's both...

I'm not a glue expert, but my quoted post above was how I understood things to be, at least until now that I'm bewildered...

I do know many woodwookers prefer white glue (PVA) due to it's long open time, and use it for things like gluing up table tops...

-Tim
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 06:21 PM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024