Porsche 911UK Forum

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

Underbody Clean & Protect

MattyR

Well-known member
Joined
21 Sep 2015
Messages
796
Hi All, I just thought I'd share this quite nifty little bit of preventative maintenance I had undertaken by D4N Detailing, Tunbridge Wells this fine Sunday afternoon. Dan of D4N has been looking after the car on a fortnightly basis for over a year now. His past life as a BMW mechanic has proven very useful; in the sense that he understands how these cars are put together and has helped with replacing trims and external items. He's also offered valuable advice on a good local mobile fitter and dent repair chap. Both top drawer.

Anyway, D4N recently got a new toy in the form of a Karcher underbody chassis cleaner. It connects to a normal pressure washer lance and is in effect a high pressure lawn sprinkler on wheels. You move it under the parts of the car you want cleaned and, hey presto, lots of 'orrible gunk removed. It has an attachment whereby one can apply a preparatory cleaner which can be left to dwell for a few mins before the main business is done (Dan used a snow foam in this instance).

After the under chassis clean, DN4 then used the first attachment, used to apply the snow foam, to under seal the car with a coat of Bilt Hamber Atom Mac corrosion inhibitor. I had the car undersealed by JZM prior to purchasing the car from them last year but 17,000 miles later and it was probably time to add to that.
 

Attachments

  • 6df435bf_bafa_460d_80b8_8a7c93f540d6_138.jpeg
    6df435bf_bafa_460d_80b8_8a7c93f540d6_138.jpeg
    1.4 MB · Views: 4,324
  • 53069649_af5b_4dec_8942_9bdc4ecd22e8_157.jpeg
    53069649_af5b_4dec_8942_9bdc4ecd22e8_157.jpeg
    1.4 MB · Views: 4,324
  • d08471e7_ffd6_4ac9_bd8d_6fbf9377eac6_362.jpeg
    d08471e7_ffd6_4ac9_bd8d_6fbf9377eac6_362.jpeg
    1.4 MB · Views: 4,324
  • ebd71aa8_bbb8_4437_982b_bdf92eaa7d09_157.jpeg
    ebd71aa8_bbb8_4437_982b_bdf92eaa7d09_157.jpeg
    1 MB · Views: 4,324
  • c94d04a8_b6c4_4cf7_a293_7d0ca3bc219f_149.jpeg
    c94d04a8_b6c4_4cf7_a293_7d0ca3bc219f_149.jpeg
    245.2 KB · Views: 4,306
Did you see how much dirt/crud was removed?
 
I should have taken a pic but it was enough to warrant getting it done that's for sure. The Bilt Hamber coating was a nice touch.
 
Did he take of the plastic under floor trays off
 
jonboy said:
Did he take of the plastic under floor trays off

No the under-trays were not removed. The trays were removed at my request prior to under-sealing by JZM. Additionally I asked the Tonbridge Porsche tech to take a look when it went in for a major service earlier on in the year. All looked good apparently :thumbs:

Next on the list is to remove the front bumper and do some preventative stuff under there.
 
zagonda said:
So basically you washed the plastic under trays ??

:grin: Not quite; as I said the trays have been off at point of purchase and additionally inspected a few months ago, so removal was not deemed necessary at present.

This was a spot of preventative maintenance to wash off any road detritus and protect any mechanical components on show. There are quite a few nooks and crannies as well as the suspension components, exhaust flanges blah blah. Worth a punt in my book but then others may not agree. Definitely something to consider alongside regular under-tray removal :thumb:
 
What stuff did JZM use when they undersealed behind the tray?
 
As above, any ideas? I've used Waxoyl in the past on Defenders but it's pretty industrial especially in Black, and maybe the wrong time of year to be applying it as it goes on thick and evaporates usually in warmth,

Mines off the road now for winter and could do with something to apply to the undercarriage, I read somewhere recently that owners apply a film of coating on the braking surface as well as the brake hoses and suspension uprights ?
 
ACF50 is the modern stuff. It's clear. Stick it in the search function on here. Lots of advocates.

I wouldn't go anywhere near brake discs or pads with anything like that personally.
 
James Thanks, That is the stuff I've seen it rings a bell, not sure if the stuff I saw applied to the brakes was a Bilt Hamber product ?? M

Like you say though, not sure I want to be putting anything on the braking surface or the pads,
 
Zingari said:
What stuff did JZM use when they undersealed behind the tray?

Hi chap, I'd have to check the paperwork from JZM but I believe they used clear Waxoyl from a compressor.
 
It is just great that folk take time to share new kit and ideas that might benefit others on forums such as this.

I have spent an inordinate amount of time crawling around under rotten cars that I owned over the years.. OK so you are asking WHY choose to do that as a pastime... well if there is no chance of affording the purchase of a sports car (long before the easy money years) you bought some end of life machine and repaired it to MOT standard it ... as the Meerkat says... simples..!

Most of the corrosion tended to be in the areas where crud collected, the obvious place was the wheel arches and beyond, more so in the days before plastic guards were fixed under the wings allowing crud to be fired at pressure behind headlight bowls and into any corner where the wing met the bodywork and elsewhere, places like pipework, fixings. brackets and other obstacles that could provide a groove or corner to hold the crud..

Porsche was about the best underseal I came across being thick and rubbery though given it was sprayed hot and relatively thick it did not get up above the headlight shells too well on early 911`s up to and including SC models, though after 1977 the galv dip process applied helped reduce corrosion considerably. So if you are thinking of paying out for a pre77 911/912 be VERY sure to check it over thoroughly for corrosion and subsequent methods of repair. I suspect buying a patchwork Porsche may have a measure of it`s structural integrity compromised to some degree relative to crash test performance..?

Thick rubbery underseal is superb if it covers the area well. The down side is if it is damaged to the extent that takes a deep cut or scrape allowing water/salt etc to attack the now bare metal, the metal can begin to corrode and that corrosion can work it`s way down behind the underseal in time creating a pocket that can hold more water, that grows in size to the extent that to repair it corroded metal has to be cut out and replaced.

Spending time inspecting underseal and keeping on top of any damage would seem to be well worth while.. Given the amount of pipework under modern water cooled power steered and air conditioned Porsches, I suspect that might provide a tad more potential for crud gathering given all the extra nooks and crannies created, though at least you have wheel arch liners and under-trays to deflect most of the crud..I suspect there is no substitute for regular inspection and cleaning, paying particular attention to the edges of metalwork where the paint will be thinnest, like the returns on the arc of the wheel arches.

Modern Porsche 911`s seem to resist corrosion rather well....Never owned 911`s beyond 82 vintage though they corroded too but nothing like the pre 77`s which could really rot big time... It seems anti corrosion measures were not perfect relative to the passage of time as even the last of the air cooled 911`s can need attention to box sections, though I wonder if that might be down to lengthy storage and condensation building up inside closed areas of the box section... Those who have cut out replaced any sections will have come across the reason for the corrosion, and might have more accurate information on the cause..?
 
Atom Mac is used on brake discs to prevent corrosion

atom-mac - Anti-Corrosion - Bilt Hamber
https://www.bilthamber.com/corrosion-protection-and-rust-treatments/atom-mac

Dilute from 2 – 5% in water and spray on surfaces to be protected. Atomise onto brake discs and surfaces after washing the vehicle and allow to dry (use 1-2% in water on motorcycles and bicycles and 5% on cars with disc brakes). Atomise into voids to protect interior surfaces at a rate of 2ml (of neat product) per litre of space. atom-mac ...
 

New Threads

Forum statistics

Threads
124,354
Messages
1,439,453
Members
48,710
Latest member
Silage
Back
Top