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All Forums >> RC Airplanes >> Composites Fabrication And Repair >> RE: Getting a smooth surface with fibreglass
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RE: Getting a smooth surface with fibreglass - 1/12/2004 11:23:32 AM   
grahamd1



Posts: 934
Joined: 7/8/2002
From: East of England, UNITED KINGDOM
Status: offline 		English Electric, in the UK Z-poxy is available (imported by Macgregor Industries).

The most common UK types of epoxy are

Pacer Z-poxy finishing resin
Ripmax Epoxy resin
Chemi-techniques finishing resin

However my own prefference is with West Systems, this can be purchased from any Chandlers (boat builders/suppliers), its great stuff.

(in reply to hnesitd1)
       Post #: 26

RE: Getting a smooth surface with fibreglass - 1/12/2004 3:24:04 PM   
English Electric


 

Posts: 17
Joined: 12/18/2003
From: London, UNITED KINGDOM
Status: offline 		Thank you. I will try and source the resin.

(in reply to grahamd1)
       Post #: 27

RE: Getting a smooth surface with fibreglass - 1/12/2004 6:17:02 PM   
grahamd1



Posts: 934
Joined: 7/8/2002
From: East of England, UNITED KINGDOM
Status: offline 		This is the UK site where the UK products have been tested

http://www.rcmodelflyers.co.uk/4um/

(in reply to English Electric)
       Post #: 28

RE: Getting a smooth surface with fibreglass - 1/13/2004 1:52:02 AM   
newbiepilot


 

Posts: 89
Joined: 12/29/2003
From: , BC,
Status: offline 		Ok, so Spackle is just premixed resin and microballoons, right? Does it have any strength in it? Could you use it to join parts together?
Thanks for the info.
I really appreciate it.

(in reply to grahamd1)
       Post #: 29

RE: Getting a smooth surface with fibreglass - 1/13/2004 2:15:23 AM   
davidfee



Posts: 691
Joined: 6/21/2003
From: San Diego, CA, USA
Status: offline 		No, spackle is not resin and microballoons. Lightweight spackle is water-based... probably an acrylic latex base of some kind (don't have a container of it to look at). It does not have much strength at all, as it is only used to fill small holes and sanding scratches. It would not work as an adhesive.

-David

< Message edited by davidfee -- 1/13/2004 2:44:01 AM >

(in reply to newbiepilot)
       Post #: 30

RE: Getting a smooth surface with fibreglass - 1/13/2004 5:37:41 PM   
FLYBOY



Posts: 8691
Joined: 1/7/2002
From: Missoula, MT, USA
Status: offline 		As stated, don't use spackle as glue. It has not strength. I use it for fillets, but when they dry and are shaped right, I go over them with CA. Also, I use micro balloons mixed with epoxy. It makes good fillets, but you need it right, they don't sand well. You end up sanding the balsa too much and the glue not enough. I lay in the mix, put alcohol on my finger and smooth it to perfect and let it set up.

Mixing micro balloons in wood glue doesn't work well. The balloons suck up the moisture and it makes a mess. I have never had any luck doing it. You can try, but I think you will find the same.

_____________________________

Fly it till the wings come off.

(in reply to davidfee)
       Post #: 31

RE: Getting a smooth surface with fibreglass - 1/14/2004 1:18:34 AM   
newbiepilot


 

Posts: 89
Joined: 12/29/2003
From: , BC,
Status: offline 		What did you mean by this then:

"Spackle is the putty you fill pinholes in your walls with (in your house) before painting. Lightweight spackle usually has microbaloons (tiny glass bubbles) in it and it is very light."

Thanks for the info.
I really appreciate it.

(in reply to davidfee)
       Post #: 32

RE: Getting a smooth surface with fibreglass - 1/14/2004 1:23:10 AM   
newbiepilot


 

Posts: 89
Joined: 12/29/2003
From: , BC,
Status: offline 		What did you mean by this then:

"Lightweight spackle usually has microbaloons (tiny glass bubbles) in it and it is very light. "

(in reply to davidfee)
       Post #: 33

RE: Getting a smooth surface with fibreglass - 1/14/2004 1:27:24 AM   
newbiepilot


 

Posts: 89
Joined: 12/29/2003
From: , BC,
Status: offline 		Woops, I posted the same question twice. Sorry about that. So can Microballoons be used for joining two parts together, for filling and for some repair.
Thanks for the info.
I really appreciate it.

(in reply to newbiepilot)
       Post #: 34

RE: Getting a smooth surface with fibreglass - 1/14/2004 1:56:40 AM   
davidfee



Posts: 691
Joined: 6/21/2003
From: San Diego, CA, USA
Status: offline 		Microballoons are just a dry filler material... they can be added to virtually any substrate. You can add them to polyester, epoxy, paint, regular wood glue... anything you want. They serve to make the resin/paint/glue more "thick" so it will stay in place. They also fill the substrate with air... the microballoons are tiny glass bubbles... so the thickened material ends up lighter. Because they are glass bubbles filled with air, they also make the cured/dried substrate easier to sand.

Microballoons and epoxy can be used to fill gaps, make fillets, bond composite panels... etc.

Microballoons and some type of water-based latex makes "lightweight spackle."
See here for lightweight spackle.

-David

(in reply to newbiepilot)
       Post #: 35

RE: RE: Getting a smooth surface with fibreglass - 1/25/2004 6:05:20 AM   
mattsimonton


 

Posts: 34
Joined: 1/24/2004
From: sapulpa, OK, USA
Status: offline 		alrighty

What is the weight difference between convenional covering and fiberglass
I was contemplating on glassing my delta vortex
I plan on putting a .91 in it so I really don't know weight would factor as much

but what is the price difference

and finally

does the same skill apply to sanding and filling glass bodys for cars(full scale)

Matt

(in reply to davidfee)
       Post #: 36

RE: RE: Getting a smooth surface with fibreglass - 1/25/2004 9:30:01 AM   
Mike James



Posts: 2438
Joined: 1/19/2002
From: Anchorage, AK, USA
Status: offline 		mateo,

I wrote to Top Flite and asked them what the weight of their applied coatings was. (without the backing material) and they said "1.8 oz./sq.yd." for the opaque colors... slightly less for transparent. You can glass a plane and match this. But... you still have to add primer and paint. (and if you're so inclined, a clear coat) A glass finish will be heavier, but obviously "better", in terms of stability, longevity, and, if you're good, realism.

The cost will be higher, for the same reason. If you buy resin by the gallon, (say, West Systems, at about $90/gal) and glass cloth in bulk, you can glass a plane for less money than Monokote. But again, you'll have to add primer, paint, and optional clear coat. Then it'll cost a little more. (But, if the price increases of these products keeps going the way it is now, it'll soon be cheaper to use composites than film covering!)

And about the finishing...
Fiberglass is fiberglass... So yes, the same skills will yield the same results. Many of us here depend on the local "body man" to do some of these tasks.

I like both methods. I wouldn't bother to glass and paint a "knock around" .40-size aerobat, but I glass ALL of my "serious" projects.

< Message edited by Mike James -- 1/25/2004 12:28:34 AM >


_____________________________

Mike James
RC Design and Building - www.nextcraft.com

(in reply to mattsimonton)
       Post #: 37

RE: Getting a smooth surface with fibreglass - 10/5/2007 6:16:14 PM   
rglawhead


 

Posts: 14
Joined: 9/30/2003
From: Marietta, GA, USA
Status: offline 		I 've just finished my first attempt at fiberglassing a model. It was a TF FW 190 D9. I used Zpoxy and .75 oz weave. It was really a lot of fun, but messy. My question concerns the amount of sanding required, ie. what is the endpoint. According to the Master (Dave Platt), you can't sand too much. I used a light finishing epoxy coat. After several swipes with a square of Nelson's 80 grit sandpaper, it appears that I have sanded away most of the fiberglass weave. I tried to sand off the bumps and gloss of the finish, thinking that it doesn't really matter if I remove most of the fiberglass. The glass is not there to provide strength, but merely to provide a smooth substrate for the paint. Right? If that is right, why don't we just seal the balsa wood and paint over it? Anyway, do I need to recoat the plane? I plan to use "Duplicolor" high build primer/filler, so I don't think I need to recoat the plane just for paint adherence. Help.

(in reply to KC-135)
       Post #: 38

RE: Getting a smooth surface with fibreglass - 10/6/2007 3:31:12 AM   
kahn41


 

Posts: 332
Joined: 5/23/2005
From: Jenison, MI, USA
Status: offline 		I beleive the glass is the strength, glass with the resin does not break very easy, just the resin does... What I use is minwax water base poly with glass. 6 coats took less time to apply than than 2 coats of resin. WB poly dries in about 10 min and a wing took me no time at all. The last thing you want to do is sand into the glass

(in reply to rglawhead)
       Post #: 39

RE: Getting a smooth surface with fibreglass - 10/6/2007 4:05:46 AM   
saramos



Posts: 2244
Joined: 12/6/2003
From: Northridge, CA, USA
Status: offline 		rg, 80 grit is too coarse. I use west systems and Duplicolor high build primer for filling the weave. I lay the glass down, brush on the epoxy with a disposable brush, squeegee off excess with those fake credit cards you get in the mail and then blot with toilet paper.
Once cured, I spray a coat of high build primer and then wet sand with 360 grit back to the top of the epoxy (don't sand too much or you can sand through the epoxy). I repeat the prime/sand process until the surface is smooth. Be sure to let the primer fully dry between coats (and especially on the last coat) or the primer will continue to dry and shrink and the weave will show again. Now the surface is ready for surface detailing and/or for a final (non high build) primer coat before painting.

Scott

(in reply to rglawhead)
       Post #: 40

RE: Getting a smooth surface with fibreglass - 10/6/2007 1:21:17 PM   
Campy