MGB Fitting a new top to a 74 MGB- how tight is too tight?

Ok... Finally got the top frame into my 1974 MGB, and got to unpack the top that's been sitting in the office for about a year now.

It's a vinyl top that I ordered from a company in Rhode Island. It's listed as a 71-80 vinyl top with zip-rear window. Looks like a decent top.

Getting the back portion of the top fastened onto the car wasn't exactly a picnic. I'd left the top out in the sun for a couple of days, but had to do quite a bit of stretching to get all the lift the dots fastened.

Now, about 1.5" (roughly) from the leading edge of the top is a thin line done in silver paint. That looks like it's a guideline for how far to pull and stretch the top, like it's supposed to match up to the front edge of the header rail and that approx 1.5" of material is to be folded under and glued to the underside of the header rail. If that's the case, it seems like the top will be tight enough to bounce a half-dollar on it. It's going to take some serious pulling and stretching on my part.

I know tops are supposed to be somewhat tight, but how tight is too tight? I know a vinyl top won't last forever, but I don't want to tear it up right out of the starting gate.

It may have had some shrinkage while sitting in the office. If the "silver line" is across the entire front, I'd be tempted to go by it. But if you think it too tight, allow a quarter of an inch less and glue it in place across the front of the header with Weldwood Contact Adhesive (the stuff for laminating Formica to counter tops). It certainly is a tedious task but tight is better than floppy.

I believe that the silver line was actually not tight enough. The front corners of the header rail were left quite exposed. So, I moved back from there roughly half an inch. Just the slightest peek of the corners are now visible. But it almost seems too tight. I haven't done anything all that permanent at this point. Haven't cut any slits or fastened the metal bar to the under side. Tempting to throw in the towel and make an early AM run to the local auto trim shop. But there would go the satisfaction of completing it myself, along with $XXX. Wish I could post pics from my phone.

wkilleffer said:

I believe that the silver line was actually not tight enough. The front corners of the header rail were left quite exposed. So, I moved back from there roughly half an inch. Just the slightest peek of the corners are now visible. But it almost seems too tight. I haven't done anything all that permanent at this point. Haven't cut any slits or fastened the metal bar to the under side. Tempting to throw in the towel and make an early AM run to the local auto trim shop. But there would go the satisfaction of completing it myself, along with $XXX. Wish I could post pics from my phone.

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Try sending your pictures to your email address, then copy/download them to your computer and post from there. I just did that with this picture:

I've done a couple tops and they come out tight. This is a Mohair top on the 72. I use clamps to get it in the right position, seen here it's in a relaxed position before gluing. Just enough gap above the windshield frame so when pulled down to latch it the top is nice and tight with no slack anywhere. This last maneuver is done in the sun to keep the top very warm, once glued and the next day pulled down to set the latches, in the sun also. it will remain tight and look nice. I did the TF the same way and it's tight also. PJ
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Been in the office for a year. Unpack and set out in sun to let it relax before doing anything. As above small steps and keep it warm.

Be careful. If I leave my TR6 top down for more than a couple of days, it takes two people pushing hard to get it back and latched. And mine was professionally installed.

Ok, got some pics. Please keep in mind that nothing has been permanently altered. No cuts in the top, haven't rivited the metal bar to the header rail. The top's in position just to show how tight or loose things may be. Also, the wrinkle across the top is less a real wrinkle and more due to the fact that this top frame seems to cant to the left a bit.

Grrr... Pics didn't make the transfer from computer to message board... Let me try again...

Ok, trying again:

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William -

Been away from the computer today. Email me the pictures (direct from your phone) and I'll see if I can post them for you. mjrichaud at gmail.com

Mickey

William's pictures:

That looks a bit strange... was the rear bar glued to the vinyl?

I've been wrong before, but it looks just a hair too small. I've used mildly shrunken/dry vinyl when I refitted the top to my my mgb, and the boot cover I bought used... is there the possibility that this top was for the wrong car? Or that the top maker just made it too small?

Hey Kenny,

To answer your questions, the rear bar was not glued to the vinyl. I got a 36" long bar @ a hardware store and cut it down trying to round the corners. Probably cut a couple of inches.

As far as too small goes, I guess it's possible, but doesn't seem probable. The receipt says it's for a 71-80 MGB with a zip rear window. It sat folded in the box for just over a year. I left it outside for two days before attempting to install.

Maybe I should go back to the silver line? It would leave more of the header rail corners exposed, but judging from the condition of the header rail, that's been done before.

Thank you,
-William

Gotta say - the tool you need at this precise moment is a credit card. I got a super deal last year on seat covers - tried to install them, they weren't a perfect fit - took them to a shop and, while I wish I could have done it myself, in truth every time I look at them I am so happy with the work they did - work I couldn't have managed on my own.

JPSmit said:

Gotta say - the tool you need at this precise moment is a credit card.

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If you can find a good local shop, this can be a really good choice. I had a local fellow do the top on my B and it fits really well.

So, just unglue everything and run it down to the trim shop I know about? Hoping to not have to spend $ like that this close to Christmas, but oh, well...

The rain gutter should be right at the front edge of the header rail. That looks to be 1.5"~ 2.0" short of where it should be.

The material will shrink over time if not fitted. As said above, the gutter needs to be at the pillar and the inner flap near the inside pillar. I would heat the top and try to stretch......but I have a feeling that it will relax and find its way back to being too small. Would not like to buy a new screen due to a top issue.
Best to purchase a Robbins and be finished.
just my 2 p.