In the process of trying to sew a haartz stayfast top for my chopped 38 Ford cabriolet. I have made a fiberglass shell to resemble a convertible top and I am now trying to cover it. I know I am going to get grief on how I am doing it, but I have my reasons. Drove a different cabriolet for many years traveling across county and in between many times. Because of all the wind noise and the top popping as I passed or was passed by tractor trailers I vowed my next cabriolet would be somewhat quiet. To be honest in the 25 years I owned my original cabriolet I only had the top down a dozen times. My problem is I am trying to develop patterns using firm plastic see through table cloths. I am getting some bunching of the plastic on the side panels and just cannot get them to stretch out. I was just wondering if anyone had some experience using stayfast material and if it will stretch out on the side panels. Don't want to cut the stayfast material until I am ready to sew. I have my own industrial machine and am able to do simple interiors and rugs, but never tried a convertible top. Any and all help and criticism appreciated.
I can get the plastic to stretch using a heat gun, but I was wondering about the stayfast material as to will it stretch.
Make relief cuts in the seams so the material will lay flat when sewing. Is this happening around corners.
No, it is happening just above where the side window ends on the curve of the top where it starts down the side. The very top piece lays nice and flat and the curve from the side to the back where the back window will fit is perfect. If I cannot shrink or stretch the stayfast I will have to made about a 3 inch long pleat in the material removing a tapered piece , which I don't want to do.
Any chance of letting me know where you purchased the Haartz material? I want to use it on my Anglia top insert. Thanks.
I did a 37 Club Cabriolet some years ago which had a top which sounds very like yours; if we're talking about your avatar pic then other than the nose it could be the same car!! Didn't use Haartz material though, we used vinyl that wasn't very stretchy, but there was some stretch to it. Center panel with hockey stick shapes sewn with a French (?) seam join. Glued straight to 'glass removable roof. Home done, worked well and looked great. Car was a total str**trod. Can't imagine you'd be able to get enough stretch, if any, out of Haarts. But, seeing as you're looking to use that, I assume you want a convertible / cabrio looking roof, in which case seams across the roof as would be necessary with hood irons etc would work fine and could look stealthily stock. As regards noise, I guess your previous dissatisfaction could have come from the flapping around that such a large expanse of roof might make. My only experience of soft tops is my '32 roadster which and has longitudinal pads to prevent flapping and works great. My 1999 Jag XK conv is so padded as to make it almost solid! But I digress! The '37 ran really quietly with the roof removed. But, and you might not wish to hear this, it was as noisy as hell with the roof on!!! Was never sure why that was! Did the sound just somehow pass by with the roof off and just reverberate back with the roof on or was it somehow the roof generating its own noise? We thought the former but were having so much fun we just lived with it! It was upholstered inside but wasn't overly insulated, if at all, if I recall. In your case I'd suggest you do the full sound insulating thing with the stick on bitumen stuff followed by the appropriate layers of the correct, sound absorbent, foams. dig in deep for the good stuff. Chris
Just went through a similar thing while doing patterns for my 31 roadster top last weekend. Used an old plastic mattress cover cut up as templates. Watched the Lebaron Bonney top installation video on you tube to use as a guide. No matter how we tried we couldn't get that material to stretch enough to come down around the B pillar area in one piece without some kind of fold, or in sewing terms a dart, at that location. Getting the actual top material to do so will be next to impossible as it is much heavier than the thin plastic. As an fyi I am using Sunbrella Supreme material. My buddy who is doing the sewing does boat tops/sails and he recommended this stuff. It has a nice flocked inner surface and looks like Haartz on the outside.
Haartz stayfast material was purchased from a company out of Mississippi named Albright's Supply. $69.00 a yard. They also have wire-on in stayfast to match the material. That is one of the main reason I went with Albright's as they had everything I needed to complete the project in stayfast. They have a catalog on line that shows everything they sell. Chris, Thanks for the info on the top. Not happy to hear the noise part. My previous cabriolet was so bad that you could not hear the radio or carry on a normal conversation. Was great traveling with my wife, but was terrible when I had a friend with me.
GordonC Thanks for the pictures. Was hoping you would say "easy to stretch". I'll try to get some pictures of my problem and perhaps someone will make a suggestion that will change my direction. Thanks again.
When I built my steel top (for my 32 Ford that was a coupe missing it's roof,) a lot of thought went into not only the styling "look", but you must always be thinking of how the material can/can't stretch. when building a roof. ...I did own a 32 Plymouth cabriolet years ago that I installed a Haartz pre-sewn top cover on it, so I recalled how & where the 4 fabric panels were joined. I don't have a good pic right now of how the side panels wrap around towards the rear, but they do come around and go to the small rectangular fabric piece around the back window. ^^^ this pic gives the basic shape of the driver side panel as it runs with the square tubing^^^ Then I used a Hidem strip at the rear "bow" so I could do a relief cut up at the top, so it could wrap around the rear of the roof. Yes, pics would help, as there are some trimmers here that can give some input on what you built/ By the way, I did a solid roof for the exact reasons you said, and mine is very quiet. The smooth header above the windshield might be part of why it is quiet.
F&J Thanks for the pics and info. That is a very nice job that you did. My problem is the area between the last two side bowes on your top - where the material of the side panel at the very top bends around to meet the flat top. Half way between your last two bowes is where my top starts to taper back to the rear bow. As a result there is an excess of material at the very top in this area. No excess on the sides, just the very top next to the flat section that lays across the top. As I have mentioned I can put in a 3 inch "dart" to remove the excess or ??????. I don't know. I really don't want to do the dart if there is some way around not doing it. Thanks again.
If you can take pics of several viewpoints where it bunches up. Maybe then the guys here that sew full time like '56Premier' can make suggestions. I've never seen a dart used on any convertible of any decade. I hope I worded it Ok in my first post.>> The side fabric pieces, where they start to turn to go behind the roof, those need a pie-cut up top, and the cut is hidden by the Hidem across the rear bow. That allows the side piece to be stretched and pulled in whatever direction that works best, while also stretching the lower part at the body. You are pulling and testing "everywhere"as you fit the side panels. I think I can see in your avatar that that area is pretty tall. If that is causing the issue, maybe make the center fabric piece come to the sides more? (meaning that if you move the final seam locations, that might help)..but pics are needed. If you had spare fabric just to lay in the tricky spots to see if any stretching would help, rather that going by that plastic? You can get cheap fabric remnants or discontinued stuff at fabric stores, or even an upholstery shop...to make test pieces. I think sewing up a test roof covering is the best way on a tricky shaped roof. The plastic stuff is throwing you off, IMO. .
I was wondering if you could make the cut for the dart at the bow? Don't know if you can use a hidem strip at the bow to cover where the edges of the seam for the dart would be.
A dart is used at the rearmost bow, under the Hidem. Not good pics ...but you should be able to understand how the side piece above the door, then turns and goes around the back of the top. You make the Hidem termination point as high as possible, and still cover the edges of the dart or "pie cut". The middle bow, if way too high? Like I mentioned before, try to bring the long seams for the center piece of the roof, closer to the sides of the car. That cuts down on how much material ''pucker" there will be at the middle bow. You can see the long side seam below: If you ran a Hidem on the middle bow too, it would look terrible.
Sorry, for the poor photo and I don't know if this will help you or not but this how my top was constructed. It is an aluminum top with the padding and top material over that. Mick
That is a perfect pic to show how the side piece of material turns and goes around to the rear window. Then if you could visualize it.... that there had to have been a pie cut in the material to be able to deal with that "pointed corner" of any rear bow on most styles of tops. (hidden under that Hidem.) Padding might get somebody out of a jamb, if the middle bow outer edge is just formed wrong with too much of a change in direction for the material to lay without bunching up.
There is an upholstery forum on the HAMB, and those folks might be able to give you some good tips. Click here: https://www.jalopyjournal.com/forum/social-forums/upholstery.153/
Thanks guys for all the suggestions and support. Took some pics today but they got stuck in a file. Hope I can get them out. No success with the pictures. I will keep trying.
Hope the pictures help with my problem. The masking tape that runs the full length of the top will represent the long seam. As suggested, I could move that long seam out closer to the edge, but I probably will still have some excessive material.
Even if the fabric would shrank that much the weave would be visibly distorted in the shrunk area. Other than designing a structure that allows the fabric to lay flat everywhere I don't see avoiding a dart.
pleats are common. I had to hand sew mine . it was "top gun " material. no stretch to it at all. I think your pleat is from wrapping around the back too far. the curve along the baseline results in too much material at the top. I would make the back a separate panel.
It looks as if you should consider moving the seams and splitting at the rear bow. The side between the #2 #3 bow seems a little square and low. Perhaps a little foam or closed cell foam there would help? I would lay the fabric I was using on there to see how it lays .I never use anything other than the materials I chose for patterns, the lay is just not the same. You don't have to cut it , just use the edges to see how it lays. The side seam will most likely not be a straight cut as well as the center may not be either. Good luck Jack
I would like thank everyone who took the time to provided some excellent information on trying to help me solve my convertible top build problem. Spent some time in the shop this past weekend trying all suggestions. Moving the long seams out further to the edge seems to work the best. By doing so most of the excessive fabric is eliminated. I am going to take a section of the stayfast material and trying steaming it to determine how much it can be stretched and also shrunk. You guys do some excellent work and have some beautiful cars. Thanks again.
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