Undertray

[tvrmallorca]

Now here's the dilemma do you powder coat the aluminium undertray or leave it bare. What I am trying to achieve is a perf ct finish that will last against the stones and other things chucked at it. Comments really appreciated... if you going to spend 100k spend it correctly is the moto I think...

[Steve_D]

If you want to treat it I would trim and drill all the panels then send them off for hard anodising. This will give far better protection. You can also get black anodised rivets.

Steve

[tvrmallorca]

I understand anodising will chip and then we have the joys of corrosion on under the anodising....what is the difference between hard and normal anodising? excuse my dumbness :-)

[k wright]

I'm going with plastic sheet that has alloy L shaped reinforcement ribs on the upper surface.

[greenamex2]

tvrmallorca said:

I understand anodising will chip and then we have the joys of corrosion on under the anodising....what is the difference between hard and normal anodising? excuse my dumbness :-)

Hard anodising leaves a MUCH thicker surface (about 5-10 times thicker) so, in theory, more resilient.

It also costs more and is arguably less attractive.

[Neptune300]

We use it all the time on race cars and boats.
Hard anodising is generally 0.038-0.042 microns thick. Can vary if required.
The coating penetrates the material by 0.020 microns (half the total thickness)
and grows 0.020 microns on surface.
It's a pain on threaded aluminium components.
You either mask threads or cut oversize.
The final colour can vary dependent on the alloy, time in tank, concentration of acid.
When I take the plunge and order a kit it's the route I will take.

[Steve_D]

Neptune300 said:

We use it all the time on race cars and boats.
Hard anodising is generally 0.038-0.042 microns thick. Can vary if required.
The coating penetrates the material by 0.020 microns (half the total thickness)
and grows 0.020 microns on surface.
It's a pain on threaded aluminium components.
You either mask threads or cut oversize.
The final colour can vary dependent on the alloy, time in tank, concentration of acid.
When I take the plunge and order a kit it's the route I will take.

What he said.
It does not chip and is a conversion process which changes the chemical structure of the material surface so there is nothing to chip off.
Have a read.
http://www.omwcorp.com/understandingano/anoindex.h...

Steve

[UltimaCH]

Thanks Steve, interesting reading.

[humble]

I'm going to use a rubberized coating like second skin on my build. It will add a little weight sure, but will do wonders for road noise and panel drumming.

Will

[Rscocca]

humble said:

I'm going to use a rubberized coating like second skin on my build. It will add a little weight sure, but will do wonders for road noise and panel drumming.

Will

This is what I did, beside, who is going to see the underside. If anyone does it might mean you are having a very bad day at the track.

I used Armartec truck bed liner, seals the under side to water as well.

[barpilot]

Rscocca said:

This is what I did, beside, who is going to see the underside. If anyone does it might mean you are having a very bad day at the track.

[EVO CL]

Do the underside panels get that much of a beating to warrant this protection? Any long term owners inspected the underside and found damage?

[F.C.]

My undercarriage is a little dirty but my missus soon put a shine on it,
She is a first rate polisher and though my underside is quite old it is in quite good nick.

[humble]

Ultimas are the kind of car that get sticky tires and sticky tires throw a lot of debris. It's really noticeable at low speeds with warm tires, but they're so loud on the road at highway speed you can't really hear it. The underside will get beat up and even anodized panels will have marks after a while. It's nothing to really worry about, just know that the panels are only perfect until the car hits the road.

Will

[tvrmallorca]

Very intsting.... however the point of keeping the underneath from chips and marks... those who know about aluminium and the corrosion of aluminium against other metal. I want to protect it and also....something hard underneath that is easy to clean with out polishing it would be great. Ideally a mirror finish would be great but unachieavable and not practical .

Will look at other ideas.... zirotech....which is ceramic coating....

[F.C.]

tvrmallorca said:

Will look at other ideas.... zirotech....which is ceramic coating....

Nice, expensive and also brittle, I'd wager it would chip off too easily when hit with road debris.

[JohnMcL]

When driving on a loose surface or grounding on something hard, deep scuffing will happen regardless of any surface coating or anodising. Better in my view is to have a sacrificial protection piece, e.g. HDPE, PP, Acetal, painted 3mm ply, or the stuff actually made for the job – 4mm Jabroc. By the time I got my car covered (800 road miles) I had several significant scratches on the undertray.

[845ste]

I who have completely redone my gtr, I sanded the frame, a color-fund chewy, and a coating powder, 7 hands.
not much expensive and it is very cost effective for many years

[F.C.]

845ste said:

I who have completely redone my gtr, I sanded the frame, a color-fund chewy, and a coating powder, 7 hands.
not much expensive and it is very cost effective for many years

Woah! I think your translator or program is a little off there.

[845ste]

F.C. you're right. my translator is not perfect
scuse me.

in any case I have done the same treatment also to undretray aluminum panels.