"Lozenge" tapes

MicroSculpt · 13 October 2009, 02:24 PM

Greetings, everyone!

Can anyone tell me if rib tapes were only cut from the edges (discard) of each bolt of printed polygon fabric? Or, whether the entire bolt was sliced up to produce both rib and edge tapes?

I look forward to the responses.

Thank you.

Tom

berman · 13 October 2009, 06:02 PM

Logic dictates that the entire roll was cut up lengthwise. There would be no scrap available from wings with the fabric applied in the direction of the chord. Some pieces might be left over from fuselage application but not enough to tape an entire aircraft. I will bet that there is a factory photo that shows a large roll of lozenge or colored tape on a table.

Maxim08 · 13 October 2009, 06:30 PM

MicroSculpt,
You will need some one such as Dan-San or Manfred T to answer emphaticly but I believe that the selvage edges of the fabric rolls are plain with only printers registration marks. These would not have the printed pattern on them. 'Lozenge' tapes that I have seen on original aircraft parts do have the printed pattern so I will go with sectioning whole fabric.
Regards,
John

'14-'18aviationcollector · 13 October 2009, 08:45 PM

Hi Tom,

I have often wondered about this too, and I have looked at some rib tapes to try to work out where in the pattern they are from. I have not been able to come up with an answer yet because when you look at the tapes it is extremeley difficult to work out where in the pattern they are from. It can be hard enough to be able to place a larger piece of fabric within the pattern, let alone the relatively thin lozenge tapes. I will have a look at some tapes and see what I might be able to tell you, but I suspect that lozenge tapes were cut from the entire pattern, not only from the edges, or from offcuts.

Regards,

David.

MicroSculpt · 13 October 2009, 08:50 PM

Thank you both!

OK, that's two for slicing up the whole width of the bolt. Makes sense to me.

Let's see if DSA or MT chime in.

Thank you.

Tom

MicroSculpt · 13 October 2009, 09:04 PM

Hi, David!

I must admit that it sounds logical that the entire bolt width would be cut.

Being an essential supply item for aircraft construction it is likely there were purpose-built machines to cut the strips to the widths required. Working with an entire bolt width seems like it would be easier. But, being ignorant of mill practices of the period that is pure speculation.

Tom

'14-'18aviationcollector · 14 October 2009, 06:17 AM

Hi Tom,

You are very welcome of course! I don't know about mill practices of the time either and I am only speculating as well but I am sure that tapes would have been specially cut. They are very uniform in width and are very straight. They certainly don't look as though they were cut as an after thought, they appear to be cut specifically for the purpose of being applied as reinforcing tapes.

I am just having a look at my sources relating to lozenge tapes now and the first thing that is obvious, although I had forgotten the extent to which this applies is that most of the lozenge tapes were removed from the AWM's Albatros and Pfalz. I remember them being stored in a drawer in the restoration shed. Sadly, I would say tragically actually, larger pieces of lozenge fabric were used to wrap some magnetos in, and they were shoved into a drawer of a beautiful old timber filing cabinet, along with piles of lozenge tapes. I was interested in studying them at the time I was involved in restoration work, but I just ran out of time. We only had a few hours on most Saturday afternoons, and I concentrated on studying the larger pieces of lozenge fabric. I had every intention of going back and looking at the lozenge tapes at a later time, but I just ran out of time. Any pieces of fabric which retain their lozenge tapes tend to be painted over, so studying them is extremely difficult. Also, the varnish of course is very heavily discoloured, so it is extremely difficult to tell which colour is under the varnish. They are all shades of smokey grey / brown, due to the discoloured varnish. I will keep looking and get back to you when I am able to find some good information.

Regards,

David.

'14-'18aviationcollector · 14 October 2009, 06:49 AM

Hi Tom,

I have found an original tape - I didn't think that I had any, to be honest. I do have some original five colour lozenge, but I didn't think that I had any tapes - actually I just thought of another piece that I have but it is just a thin strip I was given by a member of the society I worked with. It has a rib tape on it but I am not sure where it is, I haven't seen it for quite a while

Here is a picture which shows you where the tape I have just found comes from.

Maxim08 · 14 October 2009, 07:07 AM

I'll add a bit more to the fire.

Photo #1:

Photo #2

To back up my earlier comment about 'cut from the bolt', look at the tapes used on this un-restored, OAW built wing.

Photo #1 is the leading edge of the upper wing and Photo #2 is the underside of the port section of the same wing. What you maybe able to discern is a constant repeat of the pattern, not just in the leading edge tape but, in at least two of the parallel rib tapes. You wouldn't get this from various bits of off cuts but you would get this when cutting from a consistent position on a repeating pattern. BTW, the leading edge tape is a single piece running the span of the wing, ie approximately 30 feet in total.

Regards,
John

'14-'18aviationcollector · 14 October 2009, 08:13 AM

Hi John,

Excellent photos! Thank you very much for posting them! I was actually going to make a slightly different statement, that it seems to me that the tapes were cut in bulk and randomly selected and applied. Your photos suggest that maybe they were cut individually, and then applied individually (sequentially), rather than randomly, which is what I have always assumed. Still, unless each tape is examined individually it is extremely difficult to know where in the pattern they have been cut from. I was just looking at two original lozenge tapes up close, and even at short distance it is extremely difficult to be able to tell where in the pattern each piece has been cut from. I have just found another lozenge rib tape and have had a good look at it. Even up close, the blue and blue / green and the pink and purple can be extremely difficult to differentiate. I had a very close look, decided which colours are which and very quickly found where in the pattern the second lozenge rib tape has been cut from. Here is another picture which shows where it is from.

Regards,

David.