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MG MGB Technical - Convertible top issue

The abandoned project continues......I am in the process of installing a new Moss "stayfast" top. I am not understanding how to do the corners on the header rail. (Moss offers no guidence). The previous top had molded and sealed "pockets" in the vinyl, at those corners. The new one has a couple of tabs of top material attached. Any advice in MG land? Thanks, Tom
Tom in c-c-cold NY

This sounds like the OE and Don hoods. I did try to fit the header rail on mine but could not get it to fit nicely. Eventually I got a locally recommended trimmer to do it and he got it close without any wrinkles but not perfect. There were instructions with the Don hood and I will see if I can find them, I just looked on their web site and can't see them there. I also took some pics of my OE hood as I took it off the header rail, there are on another machine though.
Stan Best

Any help is welcome. Tom
Tom

Pinch out the rubber seal from its Aluminium track on the header rail. The header rail is that metal section of the roof that clips to the top of the windscreen.

Drill out the rivets that hold the aluminium track to the header rail. These must be aluminium so as not to damage the aluminium track through corrosion. It also makes them very easy to remove. Make sure you use the right size dill bit, the track is very soft. Sometimes people substitute screws which can corrode. You might prefer to cautiously drill out one rivet, and measure the hole, so you can go get some Aluminium rivets before you get too far along. You should also get some the next size up as sometimes the hole corrodes.

At either end of the header rail is a small plastic block held in place with two screws each. When the roof is up, on the car, these blocks locate on the very top of the windscreen side pillars. Use the correct screwdriver on these as they can be hard to shift. Go buy one if you haven’t got a set. Underneath the plastic blocks you will see a tab of roof material. Take a mental note of the layout. You will note that here are, in total, three tabs of roof material on each corner. The middle tab is under the plastic block, the inner, long skinny, tab is under the end of the aluminium track (a wrap around tidy the corner up). The last tab (the outer when unglued and laid out flat) was the one with the clip that you unclipped every time you took the roof down.

Peal the old roof off. Clean up the header rail to your satisfaction.
Features to note about it. At either end, on the sides, you will see an indentation. This is where the front of the side window gutters locate to reduce wind noise. Those are those bits of trim sewn on the roof, above the wind up windows.
Also you will see a hole in one end only, this is for shaking out the rivet heads (do this, otherwise they’ll rattle around every time you go around a corner).

Transfer the long metal strip from the back of the old roof/top to the new one. It slides into the pocket at the back edge.

Lay out the new roof and position the header rail on it. You’ll note the three tabs in each front corner, or infact a little back from the corners.
Use the black plastic blocks to position the front of the 'over the window gutters' in that slight recess in the header rail. There are two tabs on the hood just for that.
The middle tab wraps the roof around the end of the header rail and goes under the plastic blocks which holds it all in place. Screw down one end, then there is a small amount of stretch to get the other gutter end positioned and the tab under the plastic block.

Put the whole lot on the car as per usual. (tabs under plastic blocks keep it in place).
Clip the header rail to the windscreen as per usual, Flop the excess hood/roof over the front of the windscreen. Pull down on it firmly and mark the edge of the header rail with some chalk or water based marker. That’s the front edge where the roof will fold around the header rail.
You’ll need some adhesive.
The adhesive you use is that brush on contact adhesive. Comes in small tins, is of a yellow green slimy appearance. The sort you brush on both surfaces and than wait until it gets tacky before pressing the surfaces together. You are actually not going to do that last “waiting to get tacky” bit at all, see later.

Take it (the top/hood/roof) off the car, unscrew one plastic block and then brush a coating of contact adhesive on the front half of the header rail only. Do NOT wait for the adhesive to dry to maximum stickiness, as per its instructions. Reattach the block/tab/roof, then, while the contact adhesive is still wet and slippery (that’s why you don’t wait for it to dry), wrap pull the roof around it, about one quarter inch past the line you marked earlier. That should make the roof nice and taut when you put it back on.
How far past the line depends on how firmly you pulled down on it while marking the line, You might have to go as far as half an inch, although that is allot. This is a judgment call for you to make.

Reattach the riveted on aluminium track. You might prefer to use some temporary screws and washers instead of riveting on the track, at this stage. That’s what I did since I happened to have some the right size.

Put the whole roof back on the car and check for fit. You might want to tighten it up a bit. The contact adhesive will still be wet and not much of a problem (again, why you don’t follow the instructions on the tin).
You can tighten it up as much as you like, however you can only loosen it up about quarter of an inch before the previous rivet holes become visible

Take it off the car and rivet on the track (if you haven’t already done so)
Don’t forget to glue and wrap around the thin, under the Aluminium track tidy up tabs.
Cut off the excess roof
Pinch the rubber seal back into place. I’d strongly recommend that you get a new one as this prevents all sorts of drips and leaks. I had one that started on top of the windscreen, ran down the side pillar, behind the side pillar rubber, onto and under the dash, thence (with super natural precision) right onto my “accelerator” trouser leg.
peter

Hey Peter, thank you for your disertation. I have printed it and will follow your instructions at my first opportunity, perhaps this evening. Tom
Tom

Look carefully at the end profile of the sponge rubber seal. Both my old and new seals are 'handed' in that the two ridges that press down onto the top of the screenframe aren't symetrical, but offset very slightly. Originally the offset was towards the driver and the rear ridge kept getting trapped on top of the flange on the screen top rail. When I bought a new seal I fitted it the other way round and now it closes without getting trapped.
Paul Hunt

I now have most of the top attached. One missing link is how to wrap the bow that is just above the rear window. Loose or glued to the rib tightly? Thanks, Tom
Tom in C-C-Cold upstate NY

Glue the fabric to itself...NOT to the frame....and not too tightly. I prefer to wrap the forward flap over the rearward flap for esthetics.
Rick Ingram

Even with the two flaps wrapped round the bow and glued to each other I found the bow took up a position just behind the seam which wasn't ideal. I tied a length of braided nylon cord between the middle and rear bows, one each side, and that pulls the bow into exactly the right position. Subsequently I noticed the early removable frame had webbing doing just that, and have seen that on on marques as well.
Paul Hunt

This thread was discussed between 10/01/2009 and 22/01/2009

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