That was a year that was..

[Bfg]

Thanks Stuart & Roger.

No complaint, just an observation from someone who used to own a fibreglassing business, and took pride in the quality of their product.   And.., leaving the front catch undone (the cause of the damage) was the fault of the plonker driving the car at that particular moment.      He.. being the same plonker who'll have to fix it now.

I also have no idea who made this backlight. I bought it from a chap who had sold their primrose yellow TR6 ..who had bought it with the car. Who knows perhaps it was made sometime back in the last century ! ? 

Pete

 

 

Edited March 15 by Bfg

[Bfg]

Minor but nevertheless useful progress this afternoon.

However it started like this ! . . .

Box of screws, tippled from the shelf above and I caught it just in time ..but for a few pots stacked on top of others. I have lots of pots of screws, some stainless, some countersunk, others raised, some cheese headed, wood screws and self tappers, cross head, straight cut, you name it I've probably got some, sorted out into individual pots. And then I have all sorts of bolts, nuts, set screws, .. many of different sizes and different treads, as well as locking washers, plain washers.  And of course I have pots of clips, and bleed nipples, springs and trim clips..  So I was really lucky that only these screws fell to the floor. The fact that they caught the rubbish bin was unfortunate but again not the end of the world as we know it..

Moving on. . .

..to the polytunnel and broken bits of fibreglass...

      

Before I can repair - I need to get rid of the mastic.  Five minute job ?  in your dreams.   The black goo had excellent adhesion and wonderful elasticity.. 

Fibreglass is an incredibly useful material for making things from, but it is not the easiest stuff to get clean once it's been painted and gooed.   The issue may be identified in its other common name 'glass reinforced plastic'  .. it's the plastic which prevents chemical cleaning or seriously abrasive techniques to be applied.  It's lightweight and not very tough to clamp down, so even holding it is less than easy.  Still with craft knife to slice and shave much of the mastic off, followed by a choice of scraper, followed by shaved wire-wool I finally got there.

      

^ The inside ..where the rear fastening for the surrey top lid goes through, was painted over.  This is commonly done by the fibreglassing business to 'finish' the raw mat so that it looks better value to the paying customer.  I power-wire-brushed that off to reveal the thin layer of glass-fibres and otherwise gel.  

So cleaned, this part was ready for the first stage of 'repair'  . . .

The end of this was cracked most of the way across, so I opened up the crack and spread it with polyester glass filler.  Which is like body filler but instead of filler-power it has very fine glass fibres.  Because those glass fibres are exceptionally strong in tension, this filler paste, if it adheres well is also very strong. The random alignment of those fibres means that it doesn't crack very easily in any direction. Where the gel had been inside against the cup for the lid's fastening, I spread some more as reinforcement.  Now all I needed to do was to hold it to the right shape  . . .

 

I'd dry run with the clamps.. in this instance a strategically placed car battery, (formerly in my Chrysler diesel) which itself was being held down by the wedge of grips under the wall shelves.   The clamp (sort used to secure the tarps over market traders stands) on the side holds the flange straight for that short section, with the slightly curved tail of it hanging off the side of the shelf.

That's it for tonight. As I said not a lot but still useful to have this piece strong enough to be glued back into place in the backlight frame. The essential thing at the moment is maintaining its shape and dimension.  If I'd let this end break off then the finished width of the backlight would have been very much more difficult to get right.

   

^ a close up of the work.  It looks pretty awful but it'll clean up.  You'll note on the left hand side a fine hairline crack. That is all the way through and was opened up to spread this adhesive inside. As you can see it's closed up nicely under the weight of the car battery and upper cabinet.   It'll be left to fully cure overnight.  

So..  time for a cuppa..

Bidding you a good evening,

Pete

 

 

[stuart]

FWIW Pete I would be inclined once youve got it in one piece to bond a piece of wood in under the middle top section between the two clamp bolt plinths, I did this with mine to stop it flexing and also to give a mounting point for a high level brake light cum interior light.

Stuart.

Edited March 13 by stuart

[Bfg]

yes indeed Stuart .. just as I was planning to do.  It's back together in one piece now and so, possibly tomorrow, I'll laminated another layer of glass inside it.  And once that has set I'll add a batten of timber, which I picked up from the boat on Monday and which has been in the dry since. 

^ Bonded back together and holding its shape once again.  Nb. the black you see is gel-coat. All the mastic has been cleaned off.

^ prising out the stress cracked gel and grinding  ..to then be filled with the glass-fibre filler paste.

^ taking shape, as I rebuild the moulded edges around the top of the rear screen.

Pete

 

[john.r.davies]

Wood is intrinsically strong and flexible, and may add to the stability of your  repair.     But in glass fibre work, so does air!

Air in the sense of space, between layers of GRP.   In the same sense as length of angle iron, or a steel I-beam that is many times  stiffer than the same flat metal.   Laying GRP to form a tube will add enormously to the strength of the piece.     The flexible matt and liquid resin may be supported by material that has no strength, crushed newspaper for instance, although a cardboard former will give a neater result, and still be extremely rigid when the resin has set.

The same may be done with wood, but ensure that the glass-fibre and resin go all around it, and is not merely used to glue the wood in place.

John

Edited March 14 by john.r.davies

[Bfg]

Life grinds me down sometimes, and there's not much worse than grinding fibreglass ..as its dust (minute glass fibres) gets in places you really don't like it to.   Nevertheless, like many an unpleasant task it has to be done, and done carefully and well.  Neither filler paste nor fibreglass resin will stick well unless you cut the crud off the surface and score it.  So that was my start for today

            ..fortunately the weather's turned for the better and I can now work in the garden.  

 

   

^ at the bottom front corners (the B-post) of this backlight frame is where the first, and arguably the most important fastening, goes. However the quality of production can be seen in the crack around it.  From the above ; it's apparent that someone was trying to bond onto the top of a polished moulding (not even keyed). From the underside it's not looking much better  . . .

   

^ here the bond is gel (not fibreglass) onto a extremely lightweight moulding.  When (carefully cleaning this corner out I broke through to the outside. The panel really is that thin.  Once clean, I masking tape on the other side, and prised the crack open to apply filler paste. ^^

The other side's front corner wasn't as bad,  but it was likewise cracked.  As I say these are the most critical mounts to hold the back window onto the car, so I've reinforced them with fibreglass laminate. . .

   

^ That same left hand side ..and then similarly ^^  the right hand side.  Each now has chopped strand mat + x2 layers of woven glassfibre mat.  Naturally, I'll need to redrill the holes and retrim the bottom edges once the resin has thoroughly cured.   Btw the row of clamp seen in the first photo are an attempt to straighten that bottom edge. They are pulling the fibreglass out to a steel ruler.

Irrespective of having no core to help prevent this frame from twisting, the thickness of the fibreglass leaves something to be desired. . .

     

^ Across the top of the frame - the fibreglass flange, which hold the rear window glass in is, with gelcoat + paint, about 1mm thick.  ^^  Around the rear bottom edge and inner and outer moulding together with its bonded brings that thickness to 3mm..  the glazing rubber is of course for the thicker dimension, which is presumably why it leaked and needed copious amounts of black mastic to seal. 

    

^ The depth of the seal to fit along that flange is 12mm deep.  ^^ The second photo shows that same depth relative to the flange itself.  This was why, when I first tried fitting this backlight with its fabric top - the glass kept pulling out at the top.  When I made my fibreglass surrey-top lid(s) I made a very stiff T-bar to hold the frame back to prevent the glass from popping out. 

Now I'll address these issues.

Lunch break over, that fibreglass should have cured by now, so it's again time for more fibreglass.

Pete 

 

Edited March 14 by Bfg

[stuart]

1 hour ago, Bfg said:

Life grinds me down sometimes, and there's not much worse than grinding fibreglass ..as its dust (minute glass fibres) gets in places you really don't like it to.   Nevertheless, like many an unpleasant task it has to be done, and done carefully and well.  Neither filler paste nor fibreglass resin will stick well unless you cut the crud off the surface and score it.  So that was my start for today

            ..fortunately the weather's turned for the better and I can now work in the garden.  

 

   

^ at the bottom front corners (the B-post) of this backlight frame is where the first, and arguably the most important fastening goes. However the quality of production can be seen in the crack around it.  From above it's apparent that someone is trying to bond onto the top of a polished moulding.  from the underside it's not much better  . . .

   

^ here the bond is gel onto a single thickness of lightweight fibreglass.  When (carefully cleaning this corner out I broke through to the outside. The panel really is that thin.  Once clean, I masking tape on the other side, and prised the crack open to apply filler paste. ^^

The other side wasn't as bad,  but it was also cracked.  As I say these are the most critical mounts to hold the back window onto the car, so I've reinforced them with fibreglass laminate. . .

   

^ That same left hand side ..and then similarly ^^  the right hand side.  Each now has chopped strand mat + x2 layers of woven glassfibre mat.  Naturally, I'll need to redrill the holes and retrim the bottom edges once the resin has thoroughly cured.   Btw the row of clamp seen in the first photo are an attempt to straighten that bottom edge. They are pulling the fibreglass out to a steel ruler.

Irrespective of having no core to help prevent this frame from twisting, the thickness of the fibreglass leaves something to be desired. . .

     

^ Across the top of the frame - the fibreglass flange, which hold the rear window glass in is, with gelcoat + paint, about 1mm thick.  ^^  Around the rear bottom edge and inner and outer moulding together with its bonded brings that thickness to 3mm..  the glazing rubber is of course for the thicker dimension, which is presumably why it leaked and needed copious amounts of black mastic to seal. 

    

^ The depth of the seal to fit along that flange is 12mm deep.  ^^ The second photo shows that same depth relative to the flange itself.  This was why, when I first tried fitting this backlight with its fabric top - the glass kept pulling out at the top.  When I made my fibreglass surrey-top lid(s) I made a very stiff T-bar to hold the frame back to prevent the glass from popping out. 

Now I'll address these issues.

Lunch break over, that fibreglass should have cured by now, so it's again time for more fibreglass.

Pete 

 

FWIW Pete as you have a glass window the lip that the rubber goes on should be 10mm at least thats the rule of thumb that Moss use when assembling their glasses to fibre frames. I would also be going for a new Moss rubber when you come to refit the window. Dont forget with the Moss rubber it will appear to be bigger than the glass thats deliberate and the excess must be evenly distributed to each lower corner to prevent a gap appearing.

Stuart.

[Bfg]

44 minutes ago, stuart said:

the lip that the rubber goes on should be 10mm at least

Thanks Stuart, that's very useful to know.   I would have been guessing around 11mm to allow 1mm for tolerance, but 10mm is still probably 4mm more than it had been trimmed to before.

^ The nature of working with fibreglass is that I've deliberately extended the flange quite a bit more (that's seen as cyan blue ..as it's not cured yet). I trim it off when cured to the width required.  

^  I had hoped to do a bit more this evening, but the resin I had in stock is well passed its best.  I'll get out to buy some fresh tomorrow, as it'll make the task a dozen times easier than trying to wet out this old stuff.

Up the B-post section I've laminated x3 additional layers of 450g chopped-strand glass over the window-rubber flange. There's just one across the inside width. The flange facing into the car (seen here, facing towards the bottom clamp in the photo) isn't critical but I've reinforced over where the section of frame had ripped out.  The masking tape and weight is only there to stop the edge of that laminate from lifting, which glass fibres tends to do when bent over a 90 degree corner.

Finished early .. so it's time for a cuppa

Pete

 

 

Edited March 14 by Bfg

[stuart]

16 hours ago, Bfg said:

Thanks Stuart, that's very useful to know.   I would have been guessing around 11mm to allow 1mm for tolerance, but 10mm is still probably 4mm more than it had been trimmed to before.

^ The nature of working with fibreglass is that I've deliberately extended the flange quite a bit more (that's seen as cyan blue ..as it's not cured yet). I trim it off when cured to the width required.  

^  I had hoped to do a bit more this evening, but the resin I had in stock is well passed its best.  I'll get out to buy some fresh tomorrow, as it'll make the task a dozen times easier than trying to wet out this old stuff.

Up the B-post section I've laminated x3 additional layers of 450g chopped-strand glass over the window-rubber flange. There's just one across the inside width. The flange facing into the car (seen here, facing towards the bottom clamp in the photo) isn't critical but I've reinforced over where the section of frame had ripped out.  The masking tape and weight is only there to stop the edge of that laminate from lifting, which glass fibres tends to do when bent over a 90 degree corner.

Finished early .. so it's time for a cuppa

Pete

 

 

The 10mm lip is the size of a genuine ally frame lip so then you have more chance of everything fitting and the rubber going down into the corners correctly, dont forget its only the Moss rubber that fits correctly.

Stuart.

[Nigel C]

not been following this thread for a while and away working but had a few reminders landed in my inbox, sadly not enough time to read it all atm but what I would say (and hope I'm not repeating others) if you are fabricating areas where the rubber seal fits make sure the finished thickness of the lip is consistent as well as the width. Hopefully the rubber supplied has a larger rebate on the "body side" of the trim to allow for GRP as apposed to steel/ali. This can be done by sanding it down and make yourself a gauge/slotted piece of hardwood/plastic that you can run round the flange and check its even.

Uneven thickness/depth can affect the fitting and appearance of the finished rubber seal....go on, ask me how I know.......

 

Anyhoo, hope I haven't required your grandmother to apply a vacuum to her eggs...........

 

[stuart]

4 minutes ago, Nigel C said:

not been following this thread for a while and away working but had a few reminders landed in my inbox, sadly not enough time to read it all atm but what I would say (and hope I'm not repeating others) if you are fabricating areas where the rubber seal fits make sure the finished thickness of the lip is consistent as well as the width. Hopefully the rubber supplied has a larger rebate on the "body side" of the trim to allow for GRP as apposed to steel/ali. This can be done by sanding it down and make yourself a gauge/slotted piece of hardwood/plastic that you can run round the flange and check its even.

Uneven thickness/depth can affect the fitting and appearance of the finished rubber seal....go on, ask me how I know.......

 

Anyhoo, hope I haven't required your grandmother to apply a vacuum to her eggs...........

 

Luckily the original ally lip that that rubber was designed for is fairly thick too so it should conform.

Stuart.

[Bfg]

A quick pictorial update . . .

    

^  Fibreglassed underside to the frame, where I'd used masking tape to extend the flange.  As you can see the resultant extra width of that was 3 to 4mm and instead of being 1mm thick it is now around 3mm thick.   With the extra thickness the frame was much stiffer than it had been, so I opted to not fit wood, or other means to prevent it from twisting.  Despite my original intent, and Stuart's endorsement of doing so, the lid's T-bar worked well before to prevent twisting, and so I felt little motivation to change things. 

   

^ Having something more sturdy to work with, I got on with rebuilding the contours, and primed it.  With so many colours ; black of the moulding, grey of raw fibreglass, primrose yellow of the paintwork, and green of the fibre-filler it was difficult to see the shape.  Coating with primer added yet another colour but when first applied helped highlight flaws.  

   

^ I had considered painting the frame red, to match the car, but then because of the extent of rubber seals around all edges decided to go with gloss black.  Unfortunately, the reflections in that show up every wave and wobble in the fibreglass moulding.  I rubbed down and repainted it a couple of times but decided the odds were stacked against me.  If I were to insist on having good reflections - then this fibreglass moulding would need to be replaced with an aluminium backlight frame. 

^ If you don't take those reflections too seriously this the backlight looks acceptable for a driver's car.  I need to replace the glazing rubber's 'chrome' infill bead, as the one I have is broken and twisted.  The rubber itself I reused. Again it's far from perfect but usable.  At this stage I though the black looked good.

^ work in progress.  The backlight is now mostly refitted but it's glass has not yet 'settled'.  I could do with the heat of a closed car on a still n' sunny day to soften its glazing rubber.  There's no sealant or mastic holding the rubber in place yet, and as you can see the rear interior trim is still to be refitted.   Now on the car, I'm not so keen on the backlight being black. Perhaps it'll grow on me or else fade into the background.   We'll see.

^ Conversely, I liked the backlight being painted primrose yellow.. and its light tone disguised the moulding's numerous defects (..not only distortions but clearly its mould was chipped and at the end of its working life). 

That's all for this week, I bid you have a good weekend.

Pete

 

 

Edited March 25 by Bfg

[stuart]

5 minutes ago, Bfg said:

A quick pictorial update . . .

    

^  Fibreglassed underside to the frame, where I'd used masking tape to extend the flange.  As you can see the resultant extra width of that was 3 to 4mm and instead of being 1mm thick it is now around 3mm thick.   With the extra thickness the frame was much stiffer than it had been, so I opted to not fit wood, or other means to prevent it from twisting.  Despite my original intent, and Stuart's endorsement of doing so, the lid's T-bar worked well before to prevent twisting, and so I felt little motivation to change things. 

   

^ Having something stiffer to work with, I got on with rebuilding the contours, and primed it.  With so many colours ; black of the moulding, grey of raw fibreglass, primrose yellow of the paintwork, and green of the fibre-filler it was difficult to see the shape.  Coating with primer added yet another colour but when first applied helped highlight flaws.  

   

^ I had considered painting the frame red, to match the car, but then because of the extent of rubber seals around all edges decided to stick with gloss black.  The reflections in that, in turn showed up every wave and wobble in the fibreglass moulding.  I rubbed down and repainted it a couple of times but decided the odds were stacked against me.  If I were to insist on having good reflections - then this fibreglass moulding would need to be replaced with an aluminium backlight frame.   

^ If you don't take those reflections too seriously then the backlight looks acceptable enough for a road car.  I need to replace the 'chrome' infill bead, as the one I have is broken and twisted.  The glazing rubber I reused. Again it's far from perfect but usable.  

^ work in progress.  The backlight is now mostly refitted but it's glass is not yet 'settled'.  I could do with the heat of a closed car on a still and sunny day to soften that glazing rubber.  There's no sealant or mastic holding the rubber in place yet, and as you can see the rear interior trim is still to be refitted.   Presently I'm not sure I'm so keen on it being black, but perhaps it'll grow on me or else fade into the background and not be noticeable.   We'll see.

^ Conversely, I liked the backlight being painted primrose yellow.. and it light tone disguised the moulding's numerous defects (not only distortions but clearly its mould was chipped and at the end of its working life). 

That's all for this week, I bid you have a good weekend.

Pete

 

 

 

 

 

 

 

 

FWIW Pete white is the best colour to hide imperfections in surfaces like fibre and wouldnt look too bad against the red of the car. When I did my backlight frame I spent a lot of time blocking it off first of all then gave it a good thick coat of 2K primer which was blocked off and re-applied and so when I came to paint it it now looks exactly like an ally one and can only be distinguished by tapping it or the poly window..

Stuart.

[Bfg]

Yes indeed, most fibreglass boats are similarly white, which although a pain to keep clean in many waters ..and their decks ridiculously bright on the eyes, it does hide the imperfections. 

I wonder if your fibreglass moulding is of a better quality than this one.  Despite the repair, across the top it now looks fine. But all around the bottom it's very wavy.  I've improved its bottom front corners but had to face the fact that I'd be better off starting again (using it to make a new mould, and then taking a decent moulding out of it).  Doing that would be another time consuming project, which I really don't need nor want.  So, If the black doesn't work for me, I'll pull it off again and repaint it a cream colour.

Pete

[stuart]

39 minutes ago, Bfg said:

Yes indeed, most fibreglass boats are similarly white, which although a pain to keep clean in many waters ..and their decks ridiculously bright on the eyes, it does hide the imperfections. 

I wonder if your fibreglass moulding is of a better quality than this one.  Despite the repair, across the top it now looks fine. But all around the bottom it's very wavy.  I've improved its bottom front corners but had to face the fact that I'd be better off starting again (using it to make a new mould, and then taking a decent moulding out of it).  Doing that would be another time consuming project, which I really don't need nor want.  So, If the black doesn't work for me, I'll pull it off again and repaint it a cream colour.

Pete

I bought mine about ten years ago at least and it wasnt a particularly good moulding then and did take a lot of work to get right, I bought it as just a bare frame from Moss as back then they had a regular delivery to an MG garage in the north of the county so I could pick it up from there. Luckily at the time I was doing a resto on a 5 that had a Surrey with a mint original frame so I had that to compare with to get all the lines right. I fitted a new Honeybourne one last year and was disappointed with the finish and now theyve crept up that much in price its almost worth saving up a bit more and buying a genuine one.

Stuart.

[john.r.davies]

Nice work, Pete!

[Bfg]

Thank John, Thanks Stuart.

 

[Mk2 Chopper]

Sorry to see you've had to do this repair, but you've made a weak frame a lot better, so some solace.

Gareth