# What to do?



## Ford8loke (Jan 11, 2016)

I need your opinions on what to do with the underside of my focus rs.
Here's a pic of how it looks.

















It been stripped back to bare metal, painted with zinc primer then finished with tinted stone chip. The inner arches have been treated the same.
Should I apply some sort of sacrificial layer to protect it further? 
I already have some bh dynax ub but didn't want to affect the finished colour.
Ideally I'm looking for a product that dries clear and doesn't remaining soft/tacky collecting road debris etc etc.

Any ideas?


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## Sh1ner (May 19, 2012)

Impressive.
How far are you looking to go with protection? Just the external underside or inside the sections as well?

Whilst it is in that state and the body can be rotated and the panels gently heated with a heat gun to get wax into seams and behind welded plates etc I would use clear Waxoyl, Wax Seal, Bilt Hamber and roll the body to suit the sections/seams being treated, gently warm, let it cool and then roll the body to get the best angle for the next application. When gently heated you can really draw and wick product into seams etc.
Have you run a camera down inside the sills and sections etc? For £10 or so and a laptop I find it an excellent way of showing what you are up against. There is little point in sealing corrosion in.
It is not very often that you get the chance to get protection fully onto and into both sides of the upper surfaces of body sections and all around captive nuts etc.
I understand your desire not to cover the work but it will always be a trade off between protection and looks.
As an MOT tester I see a lot of corrosion inside pipe clips and so, would also unclip any pipes and spray inside the clips and then reclip so there are no gaps in the protection and then spray the entire underside with the same product and live with the slight colour loss.
Once it is fully dry the stickiness disappears ( takes time) and any repairs/bolts etc can be easily cleaned and then recoated if necessary. Having no problems with rusty nuts and bolts has a lot going for it.
I would do it all in one go and aim for never having to weld anything again as once it is fully waxed welding can be a fire issue so extreme care is necessary.
Also, wax can pong for a bit, the better it dries the less odour there is.
Short of galvanising correctly applied wax is the best long term protection I know of but if you are prepared to retreat regularly WD40 is surprisingly effective when sprayed into and over sections pipes etc but unfortunately doesn't last as long, still pongs but at £15 for 5 litres is cheap and easy.
I have tried flexible lacquers but they have all flaked and peeled after a while and seem to offer very little corrosion protection.


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## Ford8loke (Jan 11, 2016)

I should of stated at the beginning that the car is not and has not been on a roll over jig so I don't have the luxury of being able to rotate the body.
Neither do I have access to a ramp any more so further work will be carried out on my drive way.
The body is also now painted so I don't think heating outer panels will be possible.

I didn't think about injecting behind any clips so I'll give that a go along with treating the box sections.

The sills have been replaced and the insides were cleaned up and zinc primed.

You mentioned not sealing in any existing corrosion. So if the box sections and chassis rails etc have existing corrosion which they most likely do, how should I tackle these?


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## Sh1ner (May 19, 2012)

That is always a difficult question because once corrosion is there it is very difficult to deal with. I'm not sure there is one easy solution. 
It also depends on the amount and thickness of any corroded layers. Light surface corrosion can be treated quite well but anything a bit thicker, expanded or loose and scaly is a different proposition.

That is why the camera is so useful especially before you start. An 8mm long lead usb camera with adjustable lighting is pennies and really easy to use once you get the hang of getting it to go where you want it to.

If you have checked a section and after all this time there is little or no problem then you should able to wax with little extra effort or may consider it not worth it but if it has had new sills I would consider making sure any drains are absolutely clear and they are the one area I would perhaps fit some grommets so they can be internally waxed and then sealed again once done. Presumably they were changed because they were corroded?

In my experience rust transforming/killing waxes can work up to a point but nothing I have used can deal with layers of corrosion. It just forms a skin over the top but unless the area is completely sealed from moisture ingress then there is a route for moisture to find a way in under especially around and along seams. It just wicks its way along and makes matters worse.
If you can exclude moisture and/or oxygen you have a chance.

Personally I enjoy waxing and devising ways of getting it into awkward places or close fitting places like seams. An angled nozzle can be aimed at a seam so that warm wax can be forced in locally and then the whole cavity treated once the seams have been dealt with. That way there are no gaps.

If you are confident you can completely seal an area from water ingress then waxing would be my preferred option because once it is done it is done but that is sometimes not possible particularly where multiple panels, in layers, are welded together it is possible to do more harm than good.

I think WD40 works well because it gets into all the nooks and crannies like water and displaces water as it goes. It does all the things that water does and gets into all the places water does but without the corrosive effects.
I find it an excellent way of getting something between the layers where multiple chassis sections meet. The Sierra and the Cavalier rear ends spring to mind. Four layers in some places. Many sills have three layers inner, outer and stiffener/jacking point and if corrosion is present it is usually not good and harder to repair than two panel joins.
There are often sufficient holes in body sections to modify something like an air fed long nozzle paraffin gun or flexible plastic tubes with a self made nozzle so that seams can be directly aimed at or targeted.

Obviously once WD40 has been applied waxing directly over the top is probably not suitable unless time has passed and I'm not sure WD40 over wax achieves much but a balance of the two depending on the area being treated can work well.
So there are decisions and judgements to make and you may even decide it is all to much hassle.


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## Ford8loke (Jan 11, 2016)

Well I've decided on and started my plan of action.
For the suspension components that I had powder coated black, I've started to coat them in BH dynax ub. As they are already black the ub has little affect on the painted finish.
For the areas finished in the blue stone chip, I will be applying BH dynax uc (clear wax).
And for the cavities I'll be using BH dynax s50.

The sills as you guessed were replaced due to corrosion.
These have no factory drain holes.
Would you advise I drill some holes for drainage, treat with the s50 then seal with a grommet?


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## Sh1ner (May 19, 2012)

Sills often have drains along their length.
Little shaped sections where the panels are designed not to meet and water can drain and some air flow can happen.
Cars like the Yaris had a series of grommet filled holes along the length of the sill. They still rotted though because of multiple sections and poor rust proofing but it did make it easier for any owner so inclined to prevent any issues.
Some have none and rely on excluding water completely but condensation can still be a problem in body sections.
I am not sure there is a best way other than making sure any moisture is either vented away or cannot sit. The problem is not helped by water vapour being heavier than air that allows it to settle at the lowest points or being trapped unless it is actively vented out by airflow. Letting any vapour down and out seems to have something going for it. 


If I weld a sill section or part of I prefer to plan how to protect it after, as I do the job. Holes and grommets in strategic places (lowest points on the sills inside rear arches etc) are often a good way and can easily be properly sealed after application of any wax but I would always consider leaving a drain hole or two at the lowest points open unless you drive through rivers and streams.
When waxing I concentrate on filling any seams first as this is the area that suffers the most because it is where any water is trapped, so if it can be excluded by careful application and directing water to drain holes, that is what I aim for.
You might be lucky and be able to do a lot from the inside of the vehicle via holes in the inner sills but you will need to take into account any stiffeners and multiple panel joins ( must be treated both sides) to get the best/any protection.
I prefer warm wax (stand in a bucket of hot water until liquid) and warm panels to really try and get the product well into gaps so that water sits on and not in and then a general coat of cool product over the entire section, if necessary, to tie everything together, then leave somewhere warm to even out.
It can be messy, time consuming and if not well thought out a waste of time.
I admire your dedication to the cause.


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