Have you any opinion on "bridging" fillers - those that are filler with bits of fibreglass strands already mixed in? I have a repair to do on the corners of the fibreglass nosecone of my Firenza - someone has smoothed it to a rounded corner, when it shouldn't really be one. There's probably 5mm (or maybe a little more) missing off the corner that I need to reinstate somehow. I had a look through this thread and I can see talk of several grades of polyester filler, but no mention of this stuff.
I've also thought of using it for some of the filling that I'll need to do on the project, and the main reason for that is I was told that the bridging filler is waterproof, and the normal polyester filler is not. In talking recently to a local painter, he told me the opposite.
And finally on filling - primer first, then filler, or filler onto bare metal and then prime over it? I'd have thought the latter, but the issue then is different rates of shrinkage causing marks in the final finish. If I fill directly to bare metal, I'd be worried about damp getting through and causing trouble underneath it all.
I'd love to lead-load some of the areas as per the recent discussion in the Jowett 10 thread, but I suspect a 5' long join along my rear quarter, above the swage line, isn't the place to be learning the technique.
Have you any opinion on "bridging" fillers - those that are filler with bits of fibreglass strands already mixed in? I have a repair to do on the corners of the fibreglass nosecone of my Firenza - someone has smoothed it to a rounded corner, when it shouldn't really be one. There's probably 5mm (or maybe a little more) missing off the corner that I need to reinstate somehow. I had a look through this thread and I can see talk of several grades of polyester filler, but no mention of this stuff.
I've also thought of using it for some of the filling that I'll need to do on the project, and the main reason for that is I was told that the bridging filler is waterproof, and the normal polyester filler is not. In talking recently to a local painter, he told me the opposite.
And finally on filling - primer first, then filler, or filler onto bare metal and then prime over it? I'd have thought the latter, but the issue then is different rates of shrinkage causing marks in the final finish. If I fill directly to bare metal, I'd be worried about damp getting through and causing trouble underneath it all.
I'd love to lead-load some of the areas as per the recent discussion in the Jowett 10 thread, but I suspect a 5' long join along my rear quarter, above the swage line, isn't the place to be learning the technique.
Bridging fillers in general aren't discussed because I really don't to use them for the purpose intended i.e. bodging rust perforation in vehicle bodywork - Shock Horror Alert: But I do keep a tin of it in my stores - to use exactly for the purpose that you describe - minor fibreglass repairs to spoilers / nose cones / fibreglass panels etc and it will be fine for what you outline / intend - No its not waterproof either
Good quality filler to bare metal will be fine - the modern / good quality fillers don't shrink if used correctly i.e. mixed correctly with the recommended hardener and not applied over the top of paint surfaces / only applied to bare metal - personally if you are worried about damp effecting the filler I'd recommend waiting a little while until the better / dryer weather arrives then start with the filling / profiling process - I would recommend that you undertake this on a panel by panel basis and has you complete each panel then applying the primer with immediate effect - 'Faff' I know but it then protects the panel and the hard work that you have put into it and prevents the soul destroying effect of defective paint directly caused by damp / poor preparation. You need to consider what primer you use though - solvent based ones are porous and absorb water as do some 2 pack primers - a good quality 2 pack epoxy primer wont and will give you required protection from a damp atmosphere - However, using / applying / spraying 2 pack products is another entire can of worms from a health & safety prospective but there are safe use ways around it - let me know when you need a 'How To' (assuming that you don't already know - apologies if you do) - good luck - Chris
Thanks. I think my concern over waterproof-ness was more about the car getting a stonechip later on in life, and allowing moisture to penetrate downwards. A long shot, and a reason to keep on top of stonechips.
As for primer, I was thinking that maybe I'd roller / brush it on and then flat it. I'm not going to paint this car because I want a better finish than I can do with cellulose, but I'm hoping to do the lower layers to keep the cost down. I sprayed Epoxy onto the last car without any real issues (other than my technique / lack of experience) so I might relent on this, but I don't think so.
Thanks. I think my concern over waterproof-ness was more about the car getting a stonechip later on in life, and allowing moisture to penetrate downwards. A long shot, and a reason to keep on top of stonechips.
As for primer, I was thinking that maybe I'd roller / brush it on and then flat it. I'm not going to paint this car because I want a better finish than I can do with cellulose, but I'm hoping to do the lower layers to keep the cost down. I sprayed Epoxy onto the last car without any real issues (other than my technique / lack of experience) so I might relent on this, but I don't think so.
Roller application is far better than brush but you will need a small brush for the areas that the roller cant access - I would recommend the use of a gloss short pile mini roller - quite a lot of pro bodyshops utilise this method - ideally you still need a decent charcoal filter type mask - gloves are essential but other than that with the area well ventilated you will be fine - use a dark guide coat when you come to block it back - providing its a good quality epoxy primer it will block back fine by hand / dry
I have an issue that I keep running into, wondering if anyone can offer any advice please. I'm trying to make a repair section for the back end of a rear quarter panel, where it closes the gap to the rear valance. I've got this far with it:
It's not bad, but the top edge of it on the corner is too far "out". If that top edge lines up with the rest of the panel, then the section further down will be too far "in", it won't have the proper curved profile that is needed to make it look right. On this image
the yellow lines show roughly where it should be.
As you can see, I've had a go with a shrinker along the top edge to try to bring it in, but that's tricky to do on a curved edge and just leads to me then having to re-curve it, and get lots more marks in the metal.
Anyone have suggestions on what I can do to improve the shape please?
The annoying thing is that I've made one for the other side, and it's much, much better, and I've made them before with reasonable results. I've got a pair of fibreglass "casts" that I put the repair panel in and try to feel how far the two are away from each other, and the top edge is forcing the centre of the corner to be too flat. I wondered whether it might be time to ask for advice in case there's something I'm missing, rather than just keep bashing at it.
Sorry, I meant to add what I have - deep throat shrinker, basic fabricated English wheel (18", box section frame, small wheels) some hammers and dollies but not a shrinking hammer.
When you say "pull that into shape", the issue I have is not really knowing what that means. I can stick the dolly under it and hammer around it, but it's all a bit random. I've watched a few videos of people doing similar things, indeed the reason I bought the deep throat shrinker was to be able to do stuff like this and I watched someone making this kind of thing ("cab corner" seems to be the term) and it seemed easy.
It's only 1mm steel, I don't think I'm trying to do something impossible, it's just not going the way I hoped.
This is the video I watched before I bought the shrinker - his seems to work much better than mine does, though I expect it's his 30+ years experience too.
I had a bit of a play replicating the shape in the video, and I can get some of it with my shrinker, but it appears that the shape of the frame limits the kind of curve I can do. In theory that might not matter, but I'll play some more tomorrow.
I have watched a lot of the videos Lazze makes when I bought my shrinker/stretcher and he makes it look so easy.
I think the secret for what you are trying to do is the downward bending pressure when you first use the shrinker like he showed in your video link if you want to get the shape closer to your dotted line. A few more tries and you will get there.
I think you're right, the problem is anyone doing these videos makes it look really easy. I had a quick go at a corner like he has done and it's OK, but I think this is a limiting factor:
The section near the yellow line alters the rate of curve I can get before it starts to hit the body of the machine. His shrinker doesn't have that extra section there - it's noticeably smaller than mine, but probably more useful. Mine also takes a lot more effort to do any kind of shrink, I wonder if that's because it's not a foot-pedal one, and because the handle is quite far away from the workpiece. My shrinker jaws are also rectangular, where his are more of an oval shape, which would be much more useful for this sort of stuff.
I'm reasonably sure I can keep randomly hitting it until it gets somewhere near usable, I'm just trying to figure out how to know what to do so I can replicate it. I guess part of the issue is that I don't do stuff like this very often, so by the time I come to it again, I've forgotten how I did it. No excuse here, though, I did the other side on Friday and it seems to be OK.
Is it worth fabricating in two smaller parts to enable your shrinker to fit? What about going old school with your shrinking? Put tucks in around the edge to get your shape then lock them in and dress them down?
It's a panel I'm making for someone else, so I'm trying to avoid making it in two pieces, just because he can do that himself, or he can cut vees out and weld them up. I have considering making a tucking fork, that's another option.