8 replies to this topic

[minimininut]

Hi peeps,

So Arthur has had a little bit of rust, barely really noticeable from any distance, on the seams underneath his headlights ever since I owned him, offside slightly worse than nearside.

Looks like previous owner has touched up paint in that area before, but don't know what he did before doing that to treat the rust. I have been painting waxoyl on the paintwork to try to keep it at bay ever since I've owned Arthur (a few years) and this seems to have stopped it getting noticeably worse.









I could leave it and hope regularly applied waxoyl will stop it developing too badly. My worry is that there will be more rust going on in places I cannot see that will end up in me having to have a new front end.

So I could get the rust ground back and treated, but I'm not sure if this is the best thing to do or not? I'm uncertain because:

i) I have metallic paint work so a colour match would be difficult and it would be likely to be slightly darker than the original paintwork and maybe more noticeable than already repainted slightly waxy rusty bit!

ii) When you grind back the rust what would replace the space where the rust was? Is this what filler gets used for?!

Excuse my lack of knowledge about how body work repairs work, but if anyone has any advice / recommendations I'd appreciate it!

[donjarr]

Hi m8

That's one of those nasty places as chances are it's come from behind so will go back through the seam.

Your best bet would be to get one of those spot blasting guns which comes with rubber nozzles and recirculats the grit and hire a compressor for the weekend and slowly blast the seam clean. Then when clean paint with por15 rust prevention paint which is really good stuff, then touch up with a touch up paint stick. As for filler I would use a marine corking in black as this stay flexible unlike filler which goes hard and cracks over time and most can take paint to stop it being seen. The tricky job is going to be cleaning the back of the seam, but with the spot blasting gun they come with various rubber nozzles, so you could just cut a slot in one so the seam runs inside the nozzle and blast it clean that way. Then paint with por15 paint then when dry waxoil it.

If you don't want to go the shot blasting way a dremel with straight bristle steel wire brush and remove the rust that way then paint and seal the same.

[sonikk4]

Its unfortunate that the rust is emanating from inside the seam so its practically impossible to remove it. As you have said you have got metallic paint which is a pain to match so for the time being your best bet is to remove as small amount of paint as possible so for instance a Dremel would come into its own here.

Spot blasting would help but its keeping it down to a small enough area so i think the dremel is the way forward. You can buy good quality non silicone based automotive sealants which will allow you to over paint without any reaction. Putting filler over rusty areas is asking for trouble but if you treat the area first with a rust treatment of your choice followed by a very fine skim of filler or if the damage is minimal you may get away with some filler primer. Flat back then prime flat back topcoat and then lacquer.

No matter what you do though in time the rust will come back, it just depends on how long you can keep going until its time to replace the panels.I would try and treat the back of the seam as well and then seam seal it to prevent any more moisture ingress. Follow that with some waxoyl.

[waddle]

more of a question than a solution, im guessiing the folded bit adds strenth , otherwise you could just cut it out and weld them together like a butt weld? then there would be no seam to rust ?

[tiger99]

Almost correct, the seam adds stiffness, not necessarily strength. Hard to tell how important it is there. The front panel and inner and outer wings do carry subframe loads, and are primary structure, contrary to what some may say, but I am not sure that excessive flexing would occur if this particular joint was butt welded, especially if a stiffner was added at the outer edge to join the wing to the front, like the A panel to wing stiffner, which you should have (most people forget it, but it matters, as it makes the wings more rigid). It is only a little angle piece.

You could if necessary make an improved stiffner by butt welding the panels and then adding a stiffner cut from a single thickness of 1.8mm instead of the original two of 0.9mm. Seam welded (not structurally necessary but avoids water ingress), it would mean that the equivalent amount of metal was in the right place, but with no gap between to invite water and corrosion. I think that a similar process is used on certain seams when deseamong the shell, i.e. a false flange made of one piece oif metal is welded on the inside to replace the seam lost on the outside. (Never deseamed a shell, I think it spoils the looks.)

Oh, and something I often wonder about. It would be possible to cut out the overlaps and butt weld the joints in the wing itself where it is shaped around the headlight. Some minor hammer and dolly work to get the metal flush. I think that those particular seams are ugly. Yours, the vertical one, is rusty, and that particular seam is only so the wing could be manufactured, as without it the steel would not be sufficiently stretchable in the press. They are not flanged and do not stiffen anything.

[minimininut]

Thanks for all the info guys. I suspected it would be best to do 'something' than nothing, but in my dreams someone might have said 'it's fine, leave it alone and he'll last for ever anyway'!!

It is annoying that it is in such an awkward place - and if I remember rightly getting to the back of that area to treat anything is not all that easy either.

Anyway, Arthur is going to have some work done on the front and rear valences soon (I think it's the valence, hidden panels behind/ underneath the numberplates - when you run your hand along them bits of rust have started flaking off) so I will add the seams to the list for my car restoring miniman to do. Definitely want to put off the front end replacement as long as possible - even though I suspect it's inevitable at some point.

Cheers

[donjarr]

When doing a new front end most people overlook it now, (I'm a tad old fashioned lol) but leading the seams it the key to stopping it rust. Unlike filler lead flexes and when used with the right flux gets into every nook and cranny sealing the seam both sides. It's also useful to do things like the front bumper mounting lip where it joins the body as again this is a rust place but once leaded lasts for as long as the car.

I know some people look like you just shot their granny when you mention lead, but wear a proper mask and it's fine, and the best bit is the tallow used on the wooden tools smells like burgers cooking, so makes you hungry as well.

[sonikk4]

Lead loading is a good skill set to learn but if you use a good high grade sealant back and front of the seams then you stop all water / moisture ingress. Me personally i use aviation sealant. It sticks like the proverbial to a blanket, is temperature resistant (Gets very cold at 37,000ft) is hydraulic fluid resistant and is over paint-able.

Not easy to acquire admittedly but easier than lead loading and somewhat safer. Still would like to give lead loading a go but that's for another day.

[tiger99]

Modern body solder is lead-free. The use of lead is illegal.

One benefit of being lead-free is that you can use power tools (sanders etc) without poisoning yourself.

However, lead or its modern substitute, mostly tin, do tend to encourage dissimilar metal corrosion if the joint is exposed to moisture.