0.20 carbon veil

[frank williams]

Anybody know of a source for 0.20 oz carbon veil that doesn't charge an arm an a leg for shipping.  CST, ACP, FiberGlast, are all asking roughly $25 for shipping.  I assume its because they are pricing it as a 35+ inch package of rolled material.  For me, just wad it up and stuff it in an envelope.  Anyway, any sources would be appreciated.

[Ken Culbertson]

Got some of this earlier in the year.  It was good quality but I think it is heavier than what you are looking for.  Free shipping.

https://www.ebay.com/itm/265084734944

Lots of others there too.  Many with Free Shipping

Ken

[Tim Wescott]

Get the smallest roll of .2 oz that ACP has to offer.

You won't notice the shipping.

[Steve Dwyer]

The stuff is not cheap where ever you go and for what you have when you handle a piece of .2 oz material you wonder if you should be buying stock in the company making it.

I recently received a small order from Brodak and had a comparison sample piece of the same .2 oz weight a friend gave me he purchased from ACP. Brodak's was flimsy and wrinkled but went down fine with several coats of butyrate clear. The ACP sample was stiffer and almost looked iron pressed.  I suspect it had the sizing everyone talks about yet he has been using it for years with no problems and his finishes are top shelf. What's the real pros and cons of not requesting the "non sized" carbon veil?

Steve

[Steve Dwyer]

While on the subject of using carbon veil I have to bring up an observation I recently made. I just used carbon veil (CV) and butyrate clear on the solid flaps of my Imitation and did the same on a recently completely RD-1 plans built but covered its flaps with doctors paper (DP) and water based polyurethane. Both flaps were of equal thickness, chord dimension and of comparable weight balsa. Once fully dried I discovered both coverings had equally stiffened the flaps torsionally across the approximately same area of length. As with the CV the DP once incapsulated in the finish created a hard shell skin resisting twist. I would say as for resistance to denting they are about the same as well, not very good; the answer to this would probably be fiberglass. I have no experience here though. never used FG.

I'm sure if a pull or shear destructive test of of each material (flap) was done the CV would far exceed the DP that's why they make jets out of layers of CF. I wonder though if we can't confidently achieve the skin strength we are looking for using the less expensive DP for our purposes. Any thoughts or comments?

Steve

[Dave_Trible]

The issue here for me is shrinkage which equates to warps.  The carbon really doesn't shrink where silkspan shrinks-for decades when used with dope.  You mentioned water based paint.  Can't say what goes with that as it pertains to shrinkage.  I generally use carbon on flaps, elevators and the fuselage mostly for rigidity and usually a double layer around the nose and top deck back to the stab to eliminate a twisty rear fuselage.  The rest I silkspan.
I too got a pretty good sized roll from Ebay not long ago and the shipping didn't seem too bad however shipping ANYTHING these days is costly and has to be more of a consideration when buying.  I make my props so the cost of carbon weave, toe and a gallon of resin w/hardener ($300) makes me sweat some when I order and the shipping..............

Dave

[doug coursey]

HAS ANYBODY USED NITRATE DOPE TO STICK THE CARBON MAT DOWN....I JUST USED IT TO APPLY SILKSPAN AND IT SEEMS A LOT STICKIER THAN BUTYRATE DOPE...ITS ALMOST LIKE LIQUID GLUE....

[Brett Buck]

HAS ANYBODY USED NITRATE DOPE TO STICK THE CARBON MAT DOWN....I JUST USED IT TO APPLY SILKSPAN AND IT SEEMS A LOT STICKIER THAN BUTYRATE DOPE...ITS ALMOST LIKE LIQUID GLUE....

   Yes, that is all I have ever used, works well aside from the pinholes, which I think have nothing to do with the type of dope. There are two types of this graphite matt, one type is really smooth, uniform, and kind of stiff  and one type is sort of lumpy, uneven, and sort of fluffy. The fluffy kind is better, because it is fluffy because they use less "sizing" to hold it together, and the sizing is what causes the pinholes. ACP used to have both kinds, CST to my knowledge has only ever sold the stiff kind.


     Brett

[Tim Wescott]

... ACP used to have both kinds, CST to my knowledge has only ever sold the stiff kind. ...

In a recent moment of desperation, I found out that the sizing seems to wash out of the CST stuff with water.  Or at least it acts like wet silkspan when you get it wet, and seems "fuzzier" when it dries again.

[Steve Berry]

You can try Rockwest Composites at https://www.rockwestcomposites.com

They have it for a reasonable shipping cost (~$18 to ship to Dallas, TX) but the cost per yard is higher.

Steve

[Brett Buck]

As noted earlier, this is an opportunity for someone, for a modest investment and a little storage and postage, to make a piddling amount of money. Get, say, 100 yds, that's about 50 airplanes worth. Sell it for 1.5-2x the cost, cut to order, mailed in a big envelope for normal postage. I would do it if I had anyplace left to put a big roll of the stuff.

      Brett

[Steve Dwyer]

  The carbon really doesn't shrink where silkspan shrinks-for decades when used with dope.  You mentioned water based paint.  Can't say what goes with that as it pertains to shrinkage.  I generally use carbon on flaps, elevators and the fuselage mostly for rigidity and usually a double layer around the nose and top deck back to the stab to eliminate a twisty rear fuselage. 
Dave

Dave,
I can't respond to the possibility of shrinkage when using Minwax's water based Polyurethane. The product is used for wood floors and becomes very stiff when fully dried. I have only used it with doctors paper and not with carbon veil. I read here somewhere clear dope doesn't add much stiffness while I'd think the Polyurethane does much more so. I will add that when applying it to a long flap, the flap warps a little overnight (not twist or curl) as the water based product completely dries of the wet side. Applying to the opposite side next day removes the warp. If a little warpage remains weight it overnight and it trues out perfectly. You must, however, let the urethane dry for several days otherwise it wants to ball up instead of powdering. It does sand nicely but does require a primer to get a paint ready finish. The whole point here was to get away from the smelly dope and possibly save some money.
Steve

[frank williams]

Thanks all for your inputs.  I ordered a little of the Deluke from Gator RC.  The shipping was $4.95 ... the material is 50% heavier at 10 gms ;er m**2.   I tried one time to dope down the 0.5 oz mat.  It was  like trying to put dope on an old army blanker (if you remember those).

The thought did occur to me also Brett, that one of the garage operations could buy a roll and provide a service to the hobby.  I don't think it would damage the veil much if it were folded into a manila envelope.

I never thought about washing the sizing out.  Sounds like a mess ready to happen.

It is amazing how strong it makes a light balsa structure.  Some of the very first uses of the veil on a wing were done after the basic plane was done and the veil applied only from the fuse side out on the wing.  Not across the center section.  I caught one of those in my lap after the flyer did a corner.  It was like the wing had been cut with a bread knife right along the fuse side.  The little bitty fibers when glued down make for some incredible tensile strength.

Nitrate dope is stickier and is a well proven covering material.  Other paints seem to stick to it better.  I have a love / hate relationship with it though.  It seems to me that Nitrate just lays in wait for me.  It could be the last coat of finish and it might decide to curdle. 

[Brett Buck]

I tried one time to dope down the 0.5 oz mat.  It was  like trying to put dope on an old army blanker

   Exactly, you brush across it, and the dope just disappears into it!

      Brett

[Trostle]

My experiences with carbon matt:

For a number of years, I have had satisfactory results with the .02 oz carbon matt.  Starting with bare wood (like the fuselage and the outside surface of a cowl), I apply about 3 coats of nitrate thinned to maybe 50%.  Then apply the carbon matt with more nitrate, still thinned.  The stuff goes around compound curves extremely well.  Then apply 3 or 4 coats of more thinned nitrate before any sanding.  Then sand until the dark black disappears and turns grey.  Apply several more coats of thinned nitrate, sanding after each coat until a there is a uniform, smooth surface, then use whatever finishing technique after that to fill pinholes and some irregularities that might still appear on the surface of the matt. 

One neat thing about using nitrate as a base coat, it sticks to fillets and will NOT blister like butyrate dope will when butyrate is first applied to fillets.

Another thing about the nitrate as a base cote, it gives a harder "egg shell" surface instead of the more plastic surface that a butyrate clear base provides

The carbon matt is intended as a laminating material between two pieces of material, in our case like balsa.  It serves that purpose well.  It will certainly increase the stiffness of components laminating for instance two pieces of 1/16" balsa, cross grain to get a significant improvement in stiffness, depending on the size of the component, either CA can be used to bond the pieces of for larger pieces, finishing resin, applied very sparingly works well.

I have not found much use for the .05 oz carbon matt for the models.  Maybe it would be good for larger laminated pieces.

Just my thoughts.

Keith

[Gerald Arana]

   Exactly, you brush across it, and the dope just disappears into it!

      Brett

And if you brush across it again............you've got a ball of fur! Don't ask me how I know.
I've found the best way (for me) is to put three coats of dope down sanding the first two and use thinner over the CF mat to stick it down. Wrinkles? No problem. Use an acid brush (with dope, 50/50 is good) and tap them down (using the brush vertically). Once its stuck down proceed carefully!

Good luck, Jerry