light sources and considerations.

[caledonia]

A question often asked is what light sources are best for highlighting swirls, and there are a great many on the market which offer that ability. A popular choice is the 500W halogen light readily available from B&Q, Screwfix etc and as the photograph below highlights they are very good at highlighting swirl marks:



And also good at RDS:




However, 500W halogen lights are not completely flawless, and do have quite notable limitations when it comes to spotting lighter marring, especially hologramming left by a rotary polisher. The example below clearly highlights this.

Below is a picture of the paint finish taken using 500W halogens to assess:



The finish looks perfect! Good clarity evident. No sign of any marring. The truth of this finish is quite different however, as the Sun Gun highlights on the same area:



Very definite hologramming! And this was not evident using the halogen lights... The Sun Gun is a very reliable source of light for assessing paintwork at all angles, the 500W halogens hid these holograms at all angles of viewing and only with very careful movement of the light source and examining the finish very closely was any evidence of the marring picked up!

So if you are using 500W halogens as your sole light source, be very careful of what they can hide!


As a further example, here's the finish on the car examined with the 500W halogens both before and after the hologram removal:





No real difference at all is apparent! The Sun Gun Clearly shows that a difference has been achieved:








I know the Sun Gun is expensive, but I would strongly consider a bright light source with small area of some description for swirl spotting... Part of the halogens issue is the large light area (bright region). I find that a camera flash is very effective at highlighting hologramming - not practical, but will certainly give more confidence in the finish than 500W halogens will IMO.

Food for thought. And this is why holograms show up on cameras flashes. Due to its bright nature.

Also holograms are a sign of under worked abrasives and not refinishing down properly.
I hope this helps a few member and consider all available light sources, when gauging the true quality of your finish.
Gordon.

[Dereksjoint]

Aye my mate uses twin 500 watt halogens





Good lights but the lamps aren't good for prolonged use as they burn out quickly, a handy hint is never to touch the lamp directly with your hands when installing it into the fitting

[AGAR]

Good write-up Gordon - thats yet another thing you've taught me about detailing

[caledonia]

[Shine&Show]

good points light is very important , done a lot of work with electricians and a short spell doing quality control with powdercoating. intense focused beam is best for the marring aslo sometimes better with certain scratches and swirling others tend to spread the light to much i.e 500w halogens the 3m sun torch is awsome but can cost up to £400 if you wish a cheap alternative a good led torch is a good option these can start at a few quid upwards the Lenser T7 CREE LED is a good torch for £50 if buying an type of ligh make sure the lummens are as high as possible, saw people also using strobe lights cant comment on these never used one.

[caledonia]

Yes I have used a lenser P7 also and they are a very god torch. Very good for showing up a great number of defects.
There are a large number of good and readily available light sources, at a reasonable price. The brinkmann is another good one as you will see in my last update.

[caledonia]

Critical to ensuring you have the best possible finish when rotary polishing is assessing that the finish is hologram free - however, this is not always easy as many will know especially for light holograms... So I have compiled a few little tips and videos for how to make the best of your light source when finding holograms...


Brinkman

First off, the classic detailer's light! On the finish below, shining the light straight at the panel, we see the fine machine hologramming left in the finish from a heavy compounding stage:





The marks are there, but not obvious... to make the marring more obvious however, sweep the light source as shown in the video below and look at the clouds which move as you move the light, like moving it across a pool of water waves:



Light hologramming can be very hard to see, especially when in the small intense region of the Brinkman but moving the light as shown above highlights the marring more clearly...

Using the brighter camera flash also highlights the marring a little more:






Now, after the marring is removed, and the finish is hologram free you can see this from the pictures and there's no evidence of the hologramming when moving the light source as shown in the video:











3M Sun Gun

You might think hologramming would be easier to spot with the Sun Gun, but its still not obvious - the trick though here is not to look at the intense section of the light but instead look at the surrounding area to give you better contrast:





As above, moving the Brinkman we can see the waves like effect which highlights the hologramming clearly:



However, better still is tilting the Sun Gun, now note the clearer hologramming, a much better view:



Adding the camera flash:






Now, on the hologram free finish we can see that in the photographs, there is not evidence of marring:





The videos below show both direct light and tilted light source and both show the finish is hologram free:







Just a couple of little tricks for spotting holograms in a finish when you're working

Gordon.

[jascos]

alright bud nice job but surely if you go through all the right stages of pollishing you wont get marring in the paint work to start with.?

[caledonia]

Providing the polish is broken down fully and the car does not mar will polishing then yes.
But unfortunately all cars paints will respond totally different to polishes and combinations.

The secret is to gauge the level of correction as well as the removal rates of paint. If a car does not require a heavy cut in all panels then there is no need to do so. Save the lacquer for another day. As once it has been removed I can be put back.

We have worked on a number of German and so called hard paints and witnessed a removal rate of 4 - 5 micros of paint being removed with medium finishing polish. Now if I had to jump in a use the so called polish that my head was telling me I would need. It would have been the body shop with removal rates like that, and again how would I know the level of correction worth out different light sources.
Swirls and RDS are easy to spot. But holograms are not until its to late.
These can be cause a number of ways. But the most common are not fully working the polish, Working to large an area, working the polish at to high an speed and causing it to dry out. These will all give the same effect. Buffer trails and holograms.

Gordon.