Q-500 Racing Discuss AMA 428, AMA 424, and any other variants of Quickie 500 racing

Sheeting Foam wings

Reply

Old 12-01-2008, 03:34 AM
  #1  
freeair
Senior Member
Thread Starter
 
Join Date: May 2008
Location: queensland, AUSTRALIA
Posts: 891
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Sheeting Foam wings

just wondering if you really need to use the vacume bag method to balsa sheet a foam core wing ? i intend to buy 2 x 24 inch foam cores and sheet these with the normal 1.5 mm balsa sheets and use something like skin -it as the glue. thanks.
freeair is offline  
Reply With Quote
Old 12-01-2008, 08:17 AM
  #2  
DMyer
Senior Member
My Feedback: (2)
 
Join Date: Oct 2002
Location: Potomac, MD
Posts: 642
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

You don't have to use a vacumn bag.... I use a press(full wing length) I built years ago to squeeze the skins on under a 6" piece of laminated MDF using 1/4" allthread running through my workbench. Very cumbersome and heavy but it does an good job keeping everything straight and places quite a lot of pressure on the skins. You can even use a good board and stack a lot of weight on top (this is how it was done for years by almost everyone). Books, bricks, blocks approximating the weight of a small car(just kidding) would be about right!

That said... the vacumn bag system is by far the best, but if you are on a budget, there are alternatives that will provide acceptable results.
DMyer is offline  
Reply With Quote
Old 12-01-2008, 09:12 AM
  #3  
Scorpion Racing
Senior Member
 
Scorpion Racing's Avatar
 
Join Date: Jan 2006
Location: Winter Haven, FL
Posts: 624
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

Aww come on DMyer, you only need about 500 to 600 pounds of weight on it to do it right! You do want to pile quite a bit on it to get a good bond. I used to have a perfectly flat area (very important if you want a straight wing!) marked out on the garage floor, have the lay-up taped together, place a flat 1"x10x5' board on top and then begin adding concrete blocks, cement bags, bricks, pavers, ceramic tile or whatever I could find on top. The board on top helps keep the pressure even, and allows you to distrubute the load better. I used 500 lbs minimum.

I think the press idea is also a great way to do it, but I decided to get a vacuum instead. Either way works fine for attaching the sheeting, and I dare say that you can't tell what method was used when the wing is done.

Have fun,
Scorpion Racing is offline  
Reply With Quote
Old 12-01-2008, 10:51 AM
  #4  
EXPRESSO PYLON RACER
Senior Member
 
Join Date: May 2008
Location: LAS VEGAS, NV
Posts: 103
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

Scott are you ready for the race in several weeks
EXPRESSO PYLON RACER is offline  
Reply With Quote
Old 12-01-2008, 11:39 AM
  #5  
Scorpion Racing
Senior Member
 
Scorpion Racing's Avatar
 
Join Date: Jan 2006
Location: Winter Haven, FL
Posts: 624
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

I wish I was. I have some Scorpion kits on order, but the wings are my big hold up. They come from California and won't be here in time. I am however, about to mold the v-tail and the final fuse molds for 428 I am on the final polishing of the plugs and will lay up the molds over christmas.

Give 'em hell for me!!
Scorpion Racing is offline  
Reply With Quote
Old 12-01-2008, 12:18 PM
  #6  
luv to race
Senior Member
My Feedback: (1)
 
Join Date: Dec 2002
Location: Liquored, FL,
Posts: 678
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

So you are not coming to the Tangerine, Scott??

RB
luv to race is offline  
Reply With Quote
Old 12-01-2008, 12:55 PM
  #7  
Ed Smith
Senior Member
 
Join Date: Dec 2001
Location: Brantford, ON, CANADA
Posts: 3,305
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

just wondering if you really need to use the vacume bag method to balsa sheet a foam core wing ?
Think about this. A quicky wing has an area of 500 sq/ins. That is 500 on the top surface and 500 on the bottom surface. Total 1,000 sq/ins. I use a vacuum bag set to apply 4 #/sq/in. That is 2,000# pressure on the top and bottom of the wing. Total 4,000#. How many toolboxes, cement blocks, housebricks, books, etc, etc, etc would you have to lift on to the wing to apply that much pressure? I do it all on my worktop with no effort. When it is done I roll up the bag and put it away.

Ed S
Ed Smith is offline  
Reply With Quote
Old 12-01-2008, 02:13 PM
  #8  
vicman
My Feedback: (10)
 
vicman's Avatar
 
Join Date: Dec 2002
Location: Valdese, NC
Posts: 9,910
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

So I would need to park my Dodge Ram 4X4 on top to get similar results?
vicman is offline  
Reply With Quote
Old 12-01-2008, 02:49 PM
  #9  
Scorpion Racing
Senior Member
 
Scorpion Racing's Avatar
 
Join Date: Jan 2006
Location: Winter Haven, FL
Posts: 624
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

I am afraid not Randy. I told Gary by email, and I hate that I can't be there. This year I am going to have to step back a little, and hope my wife can find a new job so we can get out of this hole, and I can continue to race. I will still hold the events in the spring and fall, but I may not be racing much until next year. I plan to test the composites for 428, and hope in 2009 I can start in the 428 class.

Sorry Mr. WC sir...
Scorpion Racing is offline  
Reply With Quote
Old 12-01-2008, 03:05 PM
  #10  
luv to race
Senior Member
My Feedback: (1)
 
Join Date: Dec 2002
Location: Liquored, FL,
Posts: 678
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

ah, no worries Scott. family first for sure. we'll see you next time around for sure...

WC
luv to race is offline  
Reply With Quote
Old 12-01-2008, 04:45 PM
  #11  
Randy Etken
Senior Member
My Feedback: (10)
 
Randy Etken's Avatar
 
Join Date: Aug 2002
Location: Shakopee, MN
Posts: 391
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

Scott, do you have the race date for March race in Mulberry? I will be in Venice March 13 to April 9 and would love to race with you again. Let me know, I will pack up the planes.
Randy Etken is offline  
Reply With Quote
Old 12-01-2008, 06:00 PM
  #12  
Scorpion Racing
Senior Member
 
Scorpion Racing's Avatar
 
Join Date: Jan 2006
Location: Winter Haven, FL
Posts: 624
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

Randy, it should be in that range, I am waiting for the April date from the Markham park guys so that we don't conflict with their event. I will PM you with the final date as soon as I know.
Scorpion Racing is offline  
Reply With Quote
Old 12-01-2008, 08:08 PM
  #13  
j.gibson
Senior Member
 
Join Date: Jul 2008
Location: char, NC
Posts: 126
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings


ORIGINAL: luv to race

So you are not coming to the Tangerine, Scott??

RB
Randy,
John McDermott and l are coming down. J MAC will fly Q40
and l'm gonna do 424&428. l was wondering about how many entries
do you think will be there????????


Thanks, John G.
j.gibson is offline  
Reply With Quote
Old 12-01-2008, 10:29 PM
  #14  
sahartman21
 
Join Date: Nov 2007
Location: Fritch, TX
Posts: 2,060
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

I built my first racer without using a vacuum bag system. It went together O.K..

On later models they are all done with a vacuum bag system. That is the way to do it if you can get the parts. I took some pictures and wrote a how to. See below:


Building a vacuum pump and other construction tips are shown in these forums.

http://www.nmpra.org/phpBB3/viewforum.php?f=12

There is lots of good information there.
sahartman21 is offline  
Reply With Quote
Old 12-01-2008, 10:49 PM
  #15  
HighPlains
My Feedback: (1)
 
Join Date: Mar 2003
Location: Over da rainbow, KS
Posts: 5,085
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

Ed, check your concept of force again.
HighPlains is offline  
Reply With Quote
Old 12-02-2008, 02:16 AM
  #16  
freeair
Senior Member
Thread Starter
 
Join Date: May 2008
Location: queensland, AUSTRALIA
Posts: 891
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

what i can,t understand is the use of excess weight just to glue 2 surfaces together, surely if too much weight is applied to the soft foam and the soft balsa [ whats going to give ] also where is the glue going to go [ squeezed out ] . when you look at foam there is no penetration of glues to soak into the cells, also goes with balsa wood.
freeair is offline  
Reply With Quote
Old 12-02-2008, 06:42 AM
  #17  
luv to race
Senior Member
My Feedback: (1)
 
Join Date: Dec 2002
Location: Liquored, FL,
Posts: 678
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

John G. - I think we have around 20-25 signed up right now, give or take a few. And most the locals don’t pre-register.. we were originally hoping to have around 20-25 "428/422" guys, maybe more? If all our locals did show up, we'd pull about 30 pretty easily. But with the dates being close to Xmas, and the economy still hurting some.... who knows. We’ve got Dub Jett and Jerry Small coming from Texas. We’ve got Tom Scott and Craig Grunkmeyer coming from Ohio. Rusty Vanbaren coming from California. So we’ve got some national travelers headed out, which is cool of those guys coming to support. As well as you guys up in NC making the trip. Dennis O’brien throws a awesome party as well, we’ll announce that at the race.

FWIW…. Back when I started racing quickee, we built foam wing planes. And the wings were both one piece foam cores, and two piece foam cores. We have a piece of steel with a couple handles, it weighs about 65 lbs… and that’s all we used on the two piece foam core wings. The weight was not long enough for the one piece cores, so we just placed a couple gallon paint cans on the ends. Point being… it appears that we used far less weight than everyone else. And rest assured, we never had any balsa skins come lose after flying the model.

The question I have is. When you vacuum bag a set of wing cores. Do you still weight it done? To keep it from twisting? Meaning…. How do you insure that the wing (or wing half) doesn’t twist from the bag shrinking around it?

Randy Bridge
luv to race is offline  
Reply With Quote
Old 12-02-2008, 07:14 AM
  #18  
Ed Smith
Senior Member
 
Join Date: Dec 2001
Location: Brantford, ON, CANADA
Posts: 3,305
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

what i can,t understand is the use of excess weight just to glue 2 surfaces together,

The object of the exercise is to end up with a true lightweight wing. You asked where will excess glue go? The answer is obvious. Do not apply excess glue to the skins in the first place. When my skins are ready t be applied to the core the glue is barely visible, the balse has a slight damp look to it. There are no shiny (Excess) glue spots on the skin. All excess glue has been squeegeed off. The even vacuum bag pressure will ensure that all of the skin is down tight on the core surface. The pressure I apply does not crush the foam.

If you think the above is nonsense, then slop on the glue, shove it all in the bag, apply the pressure and watch the glue come up through the wood.

Ed S
Ed Smith is offline  
Reply With Quote
Old 12-02-2008, 07:16 AM
  #19  
Ed Smith
Senior Member
 
Join Date: Dec 2001
Location: Brantford, ON, CANADA
Posts: 3,305
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

Ed, check your concept of force again.

High Plains

It seemed simple to me, atmospheric pressure is all around us. If not then please educate me.

Ed S
Ed Smith is offline  
Reply With Quote
Old 12-02-2008, 08:23 AM
  #20  
Regent
Member
 
Join Date: Aug 2007
Location: , AL
Posts: 44
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

Ok guys, I know I am not the sharpest knife in the drawer but I am having trouble visualizing how you are using weights and/or clamps to apply a uniform pressure to a sheeted foam wing. It would make sense to me if anyone said that they put the sheeted wing back in the shucks. That would help apply a uniform pressure to the whole surface, but nobody mentioned that possibility. By the descriptions given, what I visualize is a wing with an airfoil shape laying on a flat surface with a flat board or whatever lying on top. It appears to me that the wing surface would have a very small footprint on both the top and bottom where the pressure would be applied.

I have sheeted foam wings in the past and have always used contact cement, usually a spray adhesive that will not attack foam on the cores and regular old brush on contact cement on the balsa sheet. After it dries past the tacky state, carefully roll it on being careful to position it right the first time because when it touches it sticks and it’s there permanently. No weights necessary, just press it down good to get out the air bubbles.

I think that the downside to using this method is the extra weight added to the wing from the contact cement and I am assuming that you folks are using some kind of epoxy. That would explain the need for weights or vacuum bagging.

When you get to be 70+ and are from the South folks need to speak slowly and distinctly for you to understand. So please type your answers very slow so I can keep up.

Thanks
Regent is offline  
Reply With Quote
Old 12-02-2008, 10:13 AM
  #21  
Scorpion Racing
Senior Member
 
Scorpion Racing's Avatar
 
Join Date: Jan 2006
Location: Winter Haven, FL
Posts: 624
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

You are correct Regent, the wing with all the internal glue, carbon fiber strips, fiberglass pieces and balsa skins are placed back in the shucks (I also add a sheet of wax paper between the shucks and the wing to aid in keeping it from sticking if any glue oozes out) and then add the weight or vacuum to it. If you vacuum it, you will need to add a couple of small weights just to ensure it doesn't move aroud any. I use 5-7 inches of vacuum on my wings and MGS epoxy resins. I also bond the foam cores into one piece, and lay up 2 layers of 2" wide 2oz. fiberglass along the trailing edge and do all the center section additional glassing UNDER the balsa skins.

As far as using adhesives other the lamination epoxy resin systems, I do not trust them. Do a test with identical sections and different adhesive types. I did this with 4 different epoxies, 2 poly glues, 2 alphatics and normal hobby store epoxy. I did them all at the same time, and placed them under the same presure for curing. I then weighed them, and did some flex and fail testing on each sample. All I will say is, I use MGS resin systems for a few very good reasons. Most either melted the foam somewhat or were to flexable or weak. I suggest you do some tests and see what will meet your needs.

Good luck with your project!
Scorpion Racing is offline  
Reply With Quote
Old 12-02-2008, 11:35 AM
  #22  
HighPlains
My Feedback: (1)
 
Join Date: Mar 2003
Location: Over da rainbow, KS
Posts: 5,085
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

Ed, if you are using 4# over 500 squares by vacuum, then it only takes 2000# of weight to do the same, not 4000#.
HighPlains is offline  
Reply With Quote
Old 12-02-2008, 11:39 AM
  #23  
garys
Senior Member
 
Join Date: Jan 2002
Location: Stansbury Park, UT
Posts: 937
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

Randy prooved a good point. While using a vacuum bag or ton of weight can help, properly done, must less weight can also lead to successful wings. I've personally used everything from very thin industrial carpet tape, to a vacuum system to sheet wings, and all worked. They each had different advantages/disadvantages to the others, but they all got the job done.

I believe the original question was can it be done without a vacuum bag..and the answer is...yes.

Ed,
If you just pulled a vacuum of 4psi on an empty bag without a wing in it, how much vacuum pressure would it have holding the two sides of the bag together?
garys is offline  
Reply With Quote
Old 12-02-2008, 11:45 AM
  #24  
HighPlains
My Feedback: (1)
 
Join Date: Mar 2003
Location: Over da rainbow, KS
Posts: 5,085
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

vacuum pressure
Some kind of oxymoron Gary?
HighPlains is offline  
Reply With Quote
Old 12-02-2008, 12:10 PM
  #25  
djlyon
Senior Member
 
Join Date: Dec 2001
Location: Castaic, CA
Posts: 2,492
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Sheeting Foam wings

I've used 3M 77 and southern sorgum without weight or vacuum successfully.[8D] And I've also used them unsuccessfully.

Denis
djlyon is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service