Page Body Text
A look inside some of the Automotive Restorers Guide
12 • AUTOMOTIVE RESTORERS GUIDE
Important Information for Chemical Brightening and Polishing of Trim Sections
To explain to those who are not aware…chemical brightening is the process of brightening the trims, which are often around the front windscreen and back screen. Likewise, these trim sections are also around the doors near to the door glass or on interior door panels, etc. Many people commonly mistake these trims as being chrome plated as they look like the bright chrome finish often found on bumpers and door handles. Searches such as classic car restoration parts are used by customers in trying to look for chemical brightening companies. Chemical brightening is where the trim item is dipped into a bath of hot acid which brightens the item, hence the name chemical brightening. The trim item is then anodised to protect the surface and keep it bright.
There are people or companies that sell different types of polish to bring the shine back to worn dull trims. In some cases, these cutting type polishes will work but…you will have to constantly keep polishing the trim as the cutting type polish will obviously remove the anodising, which protects the surface. These types of polish are not a permanent finish.
One important point to remember when you go to get your trim sections chemically brightened is that the trim sections need to have the anodising removed before you take or send them to be polished. Removing the anodising can easily be carried out by an anodising service anodising listed further on under Zinc Plating. Any anodising service would be fine for removal. The reason for removing the anodising is that it removes the hard anodised finish so that the sections can easily be polished. This is very important especially on thin delicate trim sections, as these sections need to have the least pressure put on them when polishing to avoid distortion. I have listed a company further on under Metal Polishing, for polishing. Both are experienced in classic car restoration polishing as well as classic motorcycle restoration. Once you have the anodising removed and trim sections polished you can then send to the company listed further on under Chemical Brightening.
20/21 • AUTOMOTIVE RESTORERS GUIDE
Crankshaft Straightening, Journal Repair and *Hardening
A note on crankshaft repairs If you have a damaged crankshaft where some, or all of the journals are scored beyond grinding, and it is impossible to locate a replacement one second-hand, then the journals can be built back up with either metal spraying or submerged arc welding. Damaged crankshafts are not uncommon, and often forms part of vintage or classic car restoration.
Metal spraying is a process where hot metal is sprayed onto a journal after it has been prepared. Submerged arc welding is when metal is welded onto a journal. In both cases, the repaired journals are ground back down to the correct tolerance for the bearings. Metal spraying can be carried out by the engineering listed further on under Engine Reconditioning Specialist, Engineering, Machining, *Welding, *Metal Spraying.
Metal spraying puts far less stress on a crankshaft compared to submerged arc welding. However, some views are that submerged arc welded journals are a superior job as the new metal is actually fused onto a journal by welding. Strictly speaking, a repaired crankshaft should be hardened to the same original factory original hardness.
Using hard chrome plating is often not successful for crankshaft journal repair. It is for this reason that I have not listed it.
The company below can often repair your crankshaft by submerged arc welding.
*Important
After repair work, the company below can send the crankshaft away to a specialist hardening company. When a crankshaft is re-hardened, the service is at your own risk.
The risk is that sometimes the hardening process on a repaired crankshaft can distort the crankshaft and render it useless, m