What Have I Gotten Myself Into??

[gene]

http://www.youtube.com/watch?v=4cFdPBpa3Xk

Here's a link that I have bookmarked under vinyl. It may have some helpful tips if you use a 360 degree stretch vinyl like MinUp mentioned.

I've also mentioned on here before about a video I saw where they were putting vinyl covers on auto seats and the final step was to air heat the vinyl to cause it to shrink and form a very tight fit. I don't know anything about this shrinking vinyl but it's out there somewhere.

Thanks for the info on using painter's tape, June. I will definitely put that in my possibles.

gene

[baileyuph]

Do you guys have a reference that explains the paints tape method.

My understanding has to be wrong which is:

1. cover the object with painters tape, the tape is applied in small pieces (width of 1inch or 1 1/2 inch tape and cover the entire piece.

2.  Then draw lines on the tape where you want your pattern lines to be.  Obviously, then you cut the tape along the lines. 

3.  That represents a pattern that will fit the object?  Am I correct so far?

Here is my consternation; if I take the cut tape as a pattern (which was a myriad or several widths of tape, how do you expect cutting your vinyl to that shape to fit?  The tape fits because it was a number of smaller pieces of tape.  How does that suggest using it as a pattern on a different medium would fit? 

4.  What am I missing, that would be equal to drawing lines on the form where you want seams and pinning the vinyl to the deliniated form and tracing or transferring the chalked lines to the medium, vinyl in this case.  The vinyl will not fit.

Help me out, I don't get it.

Doyle

[JuneC]

You could use plastic, paper, whatever for a pattern to cover the piece - much like Peppy uses brown paper - then cut it into pattern pieces.  If the shape is rounded, your pattern will never be flat - unless you cut it into a zillion pieces, but you can get close.  Like all patterns, it's a guide.  It will get you much closer to the actual fit than just guessing as to the shape/size.  It's certainly not foolproof, but is a valuable aid - at least to me - for complex shapes.  Try it sometime. 

You could pin the actual vinyl to the marked-up foam, but I've never had good luck with that.  There's always that one spot that the vinyl won't fit, or stretch enough, or it wrinkles, etc.

June

[gene]

In case this hasn't been mentioned, don't forget to add for the seam allowance. (Spoken from experience in making my first bolster pillows.)

gene

[Rich]

Comment on Gene's video; Maybe it's because I do this quite frequently, but I apply the glue to the entire piece and the entire back of the vinyl, allow it to dry to the touch, then attach it to the edges and then heat the center to press it into the center. That way I minimize the chance of ending up with excess to form a wrinkle. Ideally, it's best for long term adherance, to not lift the vinyl and reapply.
On the curved back, I think I see the lines in the fabric going in an "X" pattern. Using vinyl (Allsport would give the best advantage) positioned at a 45 degree angle to the back might give enough stretch to form it in one piece. I recover a lot of curved pieces called body rests on dental assistant stools and sometimes they are in one piece. On these, I always put a slight pull at each end and staple in place first, then heat and pull the vinyl into the center.
Rich

[baileyuph]

The blue tape method; thanks for the clarification, the application can have significant advantages (depending on requirements and pattern requirements.  I also like the method of using "see through" medium for pattening - clear mediums.

It seems that one should consider all their options and figure out which works for the task at hand.

Back to the subject object - given little stretch, it will have to be patterned with as many seams as required.  Done symmetrically, it will look fine and avoid using excessive heat and undue stretching.

JoJo is probably close with the 10 and 2 seams and seam around the outside back.  I would go to 8, 10, 2, and 4 o'clock locations and make it work or/also
look at sewing a stretcher from side to side, at the lower front bottom, cut to the arc of the piece for help. If that is a positive result, then just do it.  That could raise the chance of the 10 and 2 seam idea of working (eliminating the 8 and 4 seam in the face idea).

This thing can be done with seams, but one must take advantage of the limited stretch given in the medium.

The idea of a seam up and over and down the front of each arm front is looking more like a requirement.  That won't be bad to accomplish, if the foam is real firm - the easier.

Good accurate symmetric patterning, and sewing will pull this thing through.  Seam allowance is important, slightly narrow reduces bulk at the seams.  If one used clear vinyl as the patterning medium it could make it easier to trace the lines accurately.

I have seen welders piece together a myriad of metal pieces to form complex shapes, this problem isn't that extreme.  It can be done.

Neat stitching and seams located with symmetry will look just fine.  One related aspect to this issue is how much give in the foam?  That will play out in the process of patterning.

The project is starting to sound like fun!  Go for it!

Doyle

[jojo]

Thank you Doyle, this is just what I needed to hear. Almost gave up, but now it's back to the drawing board.

[bobbin]

I've never been really "comfortable" working with vinyls.  I'm fine with pretty straightforward cushion work, but anything that's really contoured makes me nervous.  At my old job I was given things like that and the estimate on the work order always made me feel that I was playing "beat the clock" (not good for creative thinking).  And I always felt pressured to make the "new" work look exactly the same as the original (with no training and few tools).  Jojo's project reminded me of that when I read the different "takes" on how to approach it.  I would be more comfortable with more pcs. (a top, bottom, "fronts" (3pcs) and maybe a back, but not knowing how the bar stools are constructed would dictate what can be done and can't.  I don't think I have the guts to go  for the glue thing, a little too "final" for this weenie (at least right now).

I've really enjoyed the discussion of a vinyl's relative stretch.  I had no idea vinyls from different manufacturers had such different stretch properties.  I use the crosshatched pattern material a lot.  But for things that will require pulling/tugging for good fit, I like clear plastic ("vapor barrier" stuff) because it "gives". 

As for patterning a very contoured shape; I "get that" mostly because of extensive garment work and training in tailoring/alterations.  Bodies are shaped, contoured, and NOT symmetrical, so in tailoring it's all about letting the shape of the form dictate the shape of pc. required to cover it.  More pcs. often means better fit; careful scrutiny of a sport coat or a bias cut evening gown demonstrates that clearly.   

[Mojo]

It takes some skill to work with vinyl and I do not have it. I have done boat interiors, golf karts, etc and the jobs came out " just OK and passable" but then I never spent alot of time learning all the tricks and idiosyncrasies of the different vinyls. I did a fair bit of work with Allsport and find that vinyl amazing with its 4 way bias.

I always marvel at June and Mike's boat interior work. No puckers, no creases and always looking like it came out of a factory. June must like this work as she is now focused on boat interiors I believe and has left the canvas work pretty much behind her.

Actually I am always amazed at all the work produced by the members here. We have some awesome masters of this trade on here.

Vinyl work is like alot of other parts of our trade. There is a learning curve.

Chris

[jojo]

Geez Chris, you just had to say "vinyl" and "curve" in the same sentence! Update: I did the backs in five pieces: an inverted triangle center, then two pieces on either side of that. It's weird because you can get the individual pattern pieces to lay nicely on the foam, but once they're sewn together it takes a lot of time and patience to get it stapled right. Anyway, lesson learned for next time. Oh, and of course I way underquoted. Par for the course.

[bobbin]

OK, so you under estimated the time required.  Who among us hasn't done that? ::)  More importantly, did you take a lot of pictures, jot down some good notes on what worked and what didn't?  You KNOW there will be another job requiring those skills! and jobs like that always seem to land in your lap as the painful memory of the last one has faded...

(it only took me about 10 yrs. to begin using the notebook system.  Now, I also use the digital camera to provide an added "visual aid"... still working on fine-tuning the filing system, though). 

Oh, and congrats! bet you're glad to see that one in the rearview mirror. 

[Highvelocity]

I'm just curious, maybe this was answered, but why couldn't you cut the material in the horseshoe shape you need.?  I mean, I know you would have a very hard time taking a straight cut and conforming it.

  Ed

[baileyuph]

There is a practical answer and a theoretical answer.

The material from a roll is a set of x-y and z coordinates with all z values equallying zero.

Then a little thought, your curvilinear form also has a set of x-y and z coordinates that any point on the shape can be referenced with respect to an origin.  Problem in fitting the two x-y and z coordinates together, or super imposing one set of corridinate over the other set of coordinates is impossible without unlimited stretch that the vinyl, in this case does not provide.

The practical test is to take a piece of material represented by a plane where z coordinates are zero (f;at that is) and it will readily be obvious that the two surfaces like the subject discussion presents will not come close to fitting.  Try it!  Also try it with your suggested shape.

This issue can get more theoretically involved, look up the mathematics of dealing with forms and transforming a three dimensional set of coordinates into a plane (where all z values are equal to zero).  Further a statistical analysis of the fit can be made. against the delta (differences in location of x-y values) that will mathematicall compute those differences which lead to wrinkles in an upholsters procedures.  The deltas, give enough stretch or undue stretch, that is in vinyls used on ATV seats. for example, can be minimized - stretched out.  Paul referenced this material in his post.

Simple but still gives understanding is; try what you suggested using vinyl that is typical -offers limited stretch in only one direction.

Seams, sometimes a lot of them are required in most of what we upholsters do.

Doyle

[jojo]

Doyle, that is what worked - pieces. And even then it took lots of heat and patience. At some point, though, I wished I were a math genius, because I was convinced that there had to be some sort of formula.
I will post a pic later today.

[baileyuph]

JoJo, I sensed you could and would do this project, you are a natural skilled person.

Abilities that are exceeded only by your modesty.

This project carried major challenge because it only had limited stretch. 

Congratulations - admirable performance!