New Silkspan From Brodak

[Mike Griffin]

With Silkspan becoming harder and harder to find, some one had posted on here that Brodak had found a source and was now selling it. So I thought I would give it a try on one plane and I ordered a few sheets.
I ordered the medium weight and when I took it out of the package, it felt more in line to the old Heavy weight we used to get from SIG.  What I did not realize until it was too late is that it has a rough side and a smooth side.  As you know, if you have ever used Polyspan, it also has an up side and a down side and if you put the wrong side up, you have a lot of wet sanding to do to take care of the fuzzes when you hit it with dope.  As luck would have it since I did not know this silkspan had different textures on each side, I put the rough side up and did not discover it till I had the wing covered.    The silkspan dried ok but when I started to brush dope on it, you almost get an orange peel texture.  It took a TON of dope to fill it and a lot of sanding with 400 grit sandpaper to get somewhat of a smooth finish.  The primer helped fill it some but it is not as smooth of a finish that you are used to with the old silkspan we used to get.

I am in no way meaning to bad mouth Brodaks at all, I just wanted to share with you what I found out kinda the hard way.  If this is the quality of Silkspan we are going to get in the future, I think the best bet would be Polyspan if you want a really nice finish.  I have been using Polyspan for years and really have had no problems at all except for that one time I put it on upside down and I got carpal tunnel from sanding so much....

Hope this helps if you did not know about it...

Mike

[Bill Little]

Hi Mike,

Thanks for the heads up! 

I have gone to almost entirely using Polyspan or silk (OTS, Classic) for open bays.  But I still use silkspan on wood surfaces to help prepare the substrate for finish.  Very seldom use the CF veil overall simply due to cost vs. effects.  The CF veil does tend to harden up the surface more than silkspan, but I do not see a real large jump in strength.  For the nose on the big stunters I still use .5 oz or so for strength applied with Z-Poxy.

I will use light silkspan or Jap tissue on 1/4A-1/2A stunters, they are a little easier to keep away from shop damage.

BIG Bear
RNMM/AMM

[Randy Cuberly]

Hey Mike,
Sorry for your problem.
Any chance Brodaks simply sent "Heavy" instead of Medium.  Is it easy to tell which side is which.
How about covering what's on there now with Jap tissue and finishing that.  Might save some sanding if it isn't too late.  You can get tissue from BMJ.

Randy Cuberly

[Dick Pacini]

It was my understanding that they only carry light and medium.  That is what their website indicates.

Perhaps medium is the new heavy.

[Mike Griffin]

Dick you are right.  I called before I ordered it and asked about heavy and they said they only had medium and light, so I ordered the medium.  It has a funny texture to it that the old silkspan did not have.  Randy I have already primed the plane and sanded the primer down and the surfaces on the solid balsa and open bays feels fairly smooth.  I think it will be OK but will let you know when I shoot the color.

The plane I covered with it was the Ted Fancher IMITATION that I have been working on for a few months now in between other life matters.   We will see but I think I will stick to Polyspan for my dope and paint finishes in the future.  I guess the good silkspan we used to know is a thing of the past now like so many other things.....

Mike

[Randy Cuberly]

Mike,
I agree completely about using Polyspan on the open bays.  However I still use silkspan on the wood portions...Fuselsage etc.

Fortunately I still have a fair supply of the old SIG Silkspan (Light and Medium Only).

The photo is my Collossus and the wings are Polyspan, everything else is lightweight silkspan.

Randy Cuberly

[Perry Rose]

Mike,can you give us a word on how the smooth side worked?

[Tim Stagg]

Mike,

It is funny you just posted this, I found out last night that there is a rough and smooth side.....oh course I have 3 bays that are smooth side up and one....on top of course that is rough side up. If there is any good news is it is on this, the right wing is the rough one so if I have to fill it more, maybe I can just eliminate the tip weight.

I had never seen this before, maybe I was just lucky before.

Tim

[Mike Griffin]

Mike,can you give us a word on how the smooth side worked?

Perry I had to do more sanding than I wanted to for fear of sanding through it but I think it will be OK. 

Mike

[Mike Griffin]

Mike,

It is funny you just posted this, I found out last night that there is a rough and smooth side.....oh course I have 3 bays that are smooth side up and one....on top of course that is rough side up. If there is any good news is it is on this, the right wing is the rough one so if I have to fill it more, maybe I can just eliminate the tip weight.

I had never seen this before, maybe I was just lucky before.

Tim

I never saw it before either with the old silk span but this new stuff is not the same.

Mike

[john e. holliday]

Some where in the shop I have colored Silkspan heavy weight I call it that has a smooth and a rough side.   It is easy to tell.   In  my years of modeling I never used much silkspan.    It was always silk,  nylon or the iron on coverings.   Best covering was the old Coverite.

[George]

OK. Now we know we need to put smooth side up...how about grain direction?

I seem to have trouble reading grain direction on the heavy stuff.

George

[Mike Griffin]

OK. Now we know we need to put smooth side up...how about grain direction?

I seem to have trouble reading grain direction on the heavy stuff.

George

Hi George

take a corner of the sheet that will not be needed, and tear it.  If it tears in a reasonably straight line, that is the way the grain is running and that is the longitudinal direction you want to install the covering from root to tip on the wing.  If when you tear it and it makes more of a jagged tear, you are going against the grain.

Mike

[Randy Cuberly]

OK. Now we know we need to put smooth side up...how about grain direction?

I seem to have trouble reading grain direction on the heavy stuff.

George

There are a couple of ways to tell grain direction.  Take a corner between your fingers of both hands and gently tear a short (and inch or so) piece and look at the tear.  If it tears reasonably straight then the grain is in the direction of the tear.  If it tears ragged and a little fuzzy then that's across the grain.

On new sheets the grain always runs along the length of the sheet (longest part).  That's due to the manufacturing process that rolls it in that direction.  If the sheet is square...tear it!

Randy Cuberly

PS:  I see Mike beat me to it!!!  Now you know!

[George]

Hi George

take a corner of the sheet that will not be needed, and tear it.  If it tears in a reasonably straight line, that is the way the grain is running and that is the longitudinal direction you want to install the covering from root to tip on the wing.  If when you tear it and it makes more of a jagged tear, you are going against the grain.

Mike

 
Mike,

I can read tissue, light silkspan and medium silkspan, but the last time I bought heavy silkspan it appeared to tear jagged in both directions. I'll assume the grain is going in the long direction.

Thanks for the tips, guys.

George

[Ward Van Duzer]

OK, so what about using polyspan on the wood structures? If you all are using poly on the open bays, why not on the wood structures? Is it about $$$? I think I'd rather be safe than sorry...

W.

[Mike Griffin]

Ward I have used Polyspan on the solid wood surfaces with good results.

Mike

[john e. holliday]

I am using the scraps of Poly-Span on the fuselage of the Ringmaster Imperial I am working on.  Where I had places that did not lay down flat I used an iron to shrink it down.  I put it on dry using dope that is almost thin as water.  Yes it takes more coats, but I know the material is getting attached better.