Fell Seam on an Awning

[Mojo]

I got in 6 awnings the other day and several are so large the upholsterer who made the older ones had to seam them in the middle. I am going to have to do the same thing as there is no fabric wide enough.

One thing I found on the old awnings is that they did a lap over seam ( for the lack of a better term ). Otherwards, they laid one section of fabric on top of the other and then ran two rows of stitching down it.

I was always under the impression that when your sewing a seam that will be under weight ( water, etc ) that you sew a fell seam ( stitched - folded then top stitched ). This awning goes on a roller tube so I was thinking that maybe they did the lap seam to cut down on the height of the seam so it didn't bulge badly when rolled up..

It just bothers me because the lap seam doesn't really seem very strong. What is the opinion of all of you ?
Would you do a fell seam or a lap seam ?

Chris

[DBR1957]

If the seam is running from the valance bar to the roller then no problem. One
benefit of a felled seam is that one stitch line is generally protected from the effects
of UV degradation and while the exposed stitchline may fail the other will hold on
much longer.

On a roll up awning the flat overlap seam is preferable for just the reason you
pointed out. Theorhetically it's supposed to be rolled up while not in use so the
stitch lines see minimal exposure. The awning frame itself can endure some rain but
not heavy downpours and the wind that comes with them. In real life we know
that some people leave these awnings opened for extended periods of time due to
a misconception of it's purpose.

As far as strength is concerned the overlap seam shouldn't cause you any
concerns. But if your customer has a tendency to leave it open for long periods
I would use seam tape and Tenara thread.

[bobbin]

Yes, Chris, you are correct in your assumption that the lapped seam is to reduce bulk when the fabric is rolled onto the tube and fully retracted.  That is how we do them in the shop where I work, although in recent years we will often have another company heat seal the panels together on really large projects. 

I would use seam sealing tape (3/4" is great) and make sure the thread you use is 100% UV treated polyester if you don't wish to go the Tenara route.  I would use 92, at least, and would actually prefer 138, personally.  (That's what I used on my recent awning project and I used a topstitched seam because they won't be wound onto a roller tube).  I ran a size 20 needle to minimize the size of the needle holes, too. 

I would also warn you that oftentimes the prewound bobbins are not UV treated, so be aware of that because in a lapped seam done on a single needle machine it's easiest to stitch one line and then flip the work over to do the other line since that way you can follow the clean selvedge edge.  Typically, I tape down the selvedge of one piece, then lay the second one over it and begin gently removing the paper from the tape working down the goods to get a nice flat seam.  I use a long arm staple to hold the two together and then stitch steadily down the run. 

[Mojo]

The seam runs parallel to the roller bar.

I will go ahead then and do a lap seam with the tape. I use tenara on all of my awnings so that shouldn't be a problem. It is hard to believe that the one single layer of Recacril would cause a bulge when the seam is running in line with the roller tube ( side to side versus front to back ). But if you all think I should do the overlap seam I will do that.

I have done a lot of awnings but the ones I am currently doing are completely different and came off an older motorcoach. What is funny is that I just finished posting this thread and got a phone call from a guy in Kentucky who wants an awning made that is identical to the one I am doing now. I tried explaining to him it would be cheaper and easier to have it done locally but he refuses and wants me to do it. It is a pain shipping these things because they have to be shipped inside tubes. I am still going to try and talk him into having it done locally.

Thanks for the information. I just wanted to make sure I was on the right track here.

Chris

[Mike8560]

U van get sunbrella in 80" widths limited colors

[fragged8]

I did a roller awning on a shop front once and used a simple
1" overlap on the seams. It worked out fine .

Rich

[Allan]

Chris

If the seam is running parallel with the roller I wouldn't think it would be a problem to do a felled seam providing you do it as close to the RV as possible so it may only have a couple of turns on the roller to stow
It shouldn't bulk up too much

Another benifit of this is when the awning is closed this is the area that cops the  sunlight all year round and hence degrades the most which means you only have to replace a thin strip to get the awning back to good again

The overlapping seam seems common on awnings but these are usually a lot smaller that what you are doing

Allan

[Mojo]

The awning is 20 ft long by 8 ft wide.

I am probably going to have to go get my Tuffsew out and set it up in the drive so I can sew this. I was planning on rolling the two pieces and then feeding them together through the machine. I see no other way and I cannot sew them in my shop because I do not have 20 ft of clearance behind me. It is going to be a royal pain.

Thanks again for all your input gang.

Chris

[BigJohn]

Chris:
     It seams to me that many manufacturers are using a vinyl coated fabric that they weld together rather than sew, and very popular right now are 2 piece awnings that have the ruffle separate from the awning making installation a lot easier.

[Darren Henry]

I am probably going to have to go get my Tuffsew out and set it up in the drive so I can sew this. I was planning on rolling the two pieces and then feeding them together through the machine. I see no other way and I cannot sew them in my shop because I do not have 20 ft of clearance behind me. It is going to be a royal pain.

These are the type of awnings I build all the time. I always use a fell seam but, I lay a thin bead of 504 latex glue in the salvage and then run it out with my finger (thin layer on each side of the salvage) and think shingles when I top stitch. I like to make the 39 1/2 " chunk the top and then fold the salvage under it so the water runs over the seam not into it.

I'd cut a piece 19' 7" by 39 ?? " to equal 8'3" after seam allowance and set it aside. I'd then cut the same length at full width and staple the 39 ??" piece in place. That way I can roll it,scrunch it , what ever and still run it through on my small table *. I then cut the valance out of the left over piece of material and insert it as a separate piece after hemming.

* I have a table 8X3 ish behind the machine to catch work,but what saves the day is a 3X4 table beside the machine with a dropleaf that fills in that void at my left elbow.This lets me feed the work without having to constantly dig it up off the floor.

[Allan]

Hey Darren and Chris

how about some pictures of these awnings for us downunder
I am thinking of maybe heading in that direction

Allan

[Mike8560]

So how did it come out mojo did you  do a  flat fell?

[Mojo]

So how did it come out mojo did you  do a  flat fell?

Hey Mike:

Sorry I didn't get back with you. Yes I did the fell seam on all of the awnings and it worked out good. I seam taped it and stitched it.

I felt better about doing the fell seam after talking with you on the phone. I rolled the dice and it seems to have worked. :) I just got two more orders for the same type of awning requiring a fell seam and overhang on the front. It makes it easier with the " portable " Juki because I can move it around and put it where I want it so I can feed long material through it.

Thanks again for your help and input. :)

Chris

[Mike8560]

CIF tour outside again on the drive goil need to get  a weather radar :)