Fulvia bonnet refurbishment

[nthomas1]

Has anyone ever removed the bracing section from the underneath of a Fulvia coupe bonnet to facilitate refurbishment?   

I once saw in a blog a picture of a bonnet and its bracing structure separated but I can't seem to find the picture now.  The attachment method on three sides seems to be only via the external weld flanges along the sides and front, so these would need to be separated (thin cutting wheel and cold chisel?).  The trickiest part may be the rear edge where the outer skin wraps over the support.   

I can work on the bonnet without separation but it would certainly make it easier to do a thorough job if I could get access to the hidden areas. However I don't want to open a Pandora's box.  As always, any advice appreciated. 

[rogerelias]

Good luck with that Norm very brave 

[nthomas1]

Brave maybe, or foolish perhaps!   Waiting to see what others say.

[Scott]

As with your sills query I think we have to assess just how bad your bonnet is ... and what level of refurbishment you're intending.

The route you're thinking of taking sounds pretty extreme and is not devoid of risks in areas being affected (warped or damaged) by trying to separate bonnet and the welded in bracing structure

So you're proposing something like the picture below but I'm trying to picture what state your bonnet is in to warrant this separation attempt that couldn't be achieved by keeping them together.


If this is a case of wanting to ensure all rust is removed and affect small repairs would a better option be to consider soda blasting (gentler than sand blasting) by a local specialist? For a relatively small item like a bonnet this shouldn't be that costly and would get everything back to bare metal to allow you to make good any localised repairs and then properly prime and paint.

[nthomas1]

Thanks Scott.  As you know, I'm fitting a new valance to the car, and today I split the weld seam between the rear panel and the valance.  A lot of force was required on some of the spot welds but I've succeeded without damaging the rear panel.  Of course I wasn't worried about damaging the valance as that is being replaced.  What the exercise has taught me is that trying to split the weld seams on the bonnet would be very difficult, if not impossible, without causing damage to the outer skin, so I'm going to proceed with my refurbishment without attempting the split.

The reason behind considering that option was that there is clearly rust under the support braces that are part of the strengthening frame, and it is difficult to get under them, and the edge braces, because there's little clearance between them and the outer skin.  However, I'll make up some flat bars to wrap sandpaper around so that I can get underneath as much as possible.   I'll then work rust-curing treatment in as best as I can - aided by gravity!   Following that I'll put waxoyl behind the braces and in the hollow sections.

[Scott]

That makes a lot of sense.
There might still be a case for soda blasting as that will reach parts otherwise difficult to reach if it proves a nightmare. Otherwise get a job lot of emery boards from your local nail bar emporium! 

I mentioned in the sill subject but if you haven't come across it I'd highly recommend POR-15 http://www.por15.com/POR-15_Rust_Preventive_Coating . This is really effective and if there's any concern there a small lingering amount of surface rust you simply can't get to but you can get a paint brush in or pour some of the POR over it then this will seal it for good. I could tell you a story about making sure you wear suitable protection when using it but that's a story for another time...! 

Inferring from your forum posts you're coming along well; post some pictures when you can as I'm sure we'd all like to see them. I'm also someone who brought a reasonable but slightly tatty Fulvia many years ago and self-restored. It's a great car to work on with some super engineering and I can see why you want to get things right. Good luck!

[nthomas1]

Thanks for the pointers Scott.   I'll check out soda blasting options in this area (Lancashire).  I've been using Kurust and Hammerite "Paint-on-Rust" paint so far in my restoration.  From your comments I assume you rate the POR product more highly.

Had a rather odd experience when working on the car today.   While working on the refurbishment of the hood (picture 1),  I found what looked like pieces of coal or charcoal falling out of the support frame that supports the hood (picture 2).  I was running sanding sheets attached to a strip of metal under the edges to work on the hidden rust when these hard lumps came out. Could just about slot my fingers under the edge and feel the hard substance still in situ in some places.  Some probing with a hook-ended tool broke it free. I found some short sections of material, similar to carpet felt (picture 3), that were still flexible, though only slightly.

It seems that the cross braces, which are a sort of inverted "U" shape, have been filled at some stage with either: (1) a fibre strip that in most places had solidified and gone brittle (petrified?), or (2) two different materials, a hard material plus the fibre strip. Strange!

I assume the material(s) were put in place as sound deadening by a previous owner. The materials were not just tucked under the braces but had actually been cut to fit snugly in the inverted "U" sections.   Or is it possible that the materials were factory-installed?

 

[fay66]

Thanks for the pointers Scott.   I'll check out soda blasting options in this area (Lancashire).  I've been using Kurust and Hammerite "Paint-on-Rust" paint so far in my restoration.  From your comments I assume you rate the POR product more highly.

Had a rather odd experience when working on the car today.   While working on the refurbishment of the hood (picture 1),  I found what looked like pieces of coal or charcoal falling out of the support frame that supports the hood (picture 2).  I was running sanding sheets attached to a strip of metal under the edges to work on the hidden rust when these hard lumps came out. Could just about slot my fingers under the edge and feel the hard substance still in situ in some places.  Some probing with a hook-ended tool broke it free. I found some short sections of material, similar to carpet felt (picture 3), that were still flexible, though only slightly.

It seems that the cross braces, which are a sort of inverted "U" shape, have been filled at some stage with either: (1) a fibre strip that in most places had solidified and gone brittle (petrified?), or (2) two different materials, a hard material plus the fibre strip. Strange!

I assume the material(s) were put in place as sound deadening by a previous owner. The materials were not just tucked under the braces but had actually been cut to fit snugly in the inverted "U" sections.   Or is it possible that the materials were factory-installed?

 

Norman,
It would have been part of the original manufacturing process, have a look at the deadener that is used elsewhere which is similar, the hard lumps would appear to be the hardened adhesive.
I've been soaking underneath the bracing on "Fay" with Dinitrol antirust for the past 17 years with no further problems, and other areas with a mixture of spray Dinitrol or brushed waxoyl depending on accessibility, the inverted U shape is just to stiffen the component.

Brian
8227

[stanley sweet]

Yes - definitely soda blasting if you go that route. I once saw a Fulvia that had had its aluminium bonnet sandblasted. Imagine draping a wet sheet ovet the bonnet frame and that's what it looked like.

[Barry.Cook]

Hi Norman,
                 If you find someone locally who does soda blasting could you let me know. I use a small outfit in Longton for grit blasting and powder coating but they don't do soda blasting.

Regards,
             Barry

[nthomas1]

Hi Barry - I briefly researched soda blasting in the North West - but the companies I found were doing soda blasting of masonry.  In the end I decided to strip the bonnet myself.  I followed Scott's advice to get a load of abrasive paper (Scott jokingly suggested emery boards). I've been learning, as I progress with my novice rebuild, that you have to improvise a lot.  Working on the bonnet I used the tools shown in the attached picture, plus a large Bowie knife (I lived in Tennessee for six years!) that has a curved blade which is great for scraping along concave curved surfaces like the edges of the bonnet bracing structure.  The panel saw was very useful to slide under the bracing and into the perimeter of the bonnet where the bracing is welded to the outer skin.   Sliding it along loosened surface rust, and covering it with oxide paper allowed me to sand in those narrow gaps. The two home made sponge applicators were knocked together from a wire coat hanger and a car-wash sponge.  They allowed me to get rust treatment fluid into those same gaps. The Ryobi multi-tool has proved priceless in many applications on the car.  I used it to remove sprayed-on underseal from the bonnet underside, and I have used it to remove sound-deadening from the roof after I removed the headliner, and also to remove underseal from the underside of the floor of the car and the wheel arches. 
Cheers, Norm

[simonandjuliet]

The multitool doesn't damage the surface of the panel ?

I might have to try that !

[nthomas1]

If held at a shallow angle the scraper blade doesn't damage the metal, but if presented at too steep an angle it can dig in.  I'm only using it on surfaces that will be covered: the bonnet underside which will be covered with sound deadening material, the roof which will be hidden by the headliner, and the underbody which will be covered with underseal.
 

[davidwheeler]

If you have a compressor you can buy a gun in Machine Mart and sod bicarb on the internet and do it yourself - it is not difficult!   On the other hand, soda is not sufficiently brasive for steel but is ideal for aluminium.  My technique (on steel) was to use paint stripper and then a wire brush in the angle grinder.

[nthomas1]

Thanks David - but unfortunately I have no power in my garage. I own the top half of a Victorian house, and my garage is at the bottom of the garden.  I'd need an extension lead about 120 foot long and would have to drape it over the garden of the people who have the lower part of the house, so I do all my work in daylight and with battery powered tools.  I use Ryobi 18v tools and I have 5 batteries which I charge every evening!