Q W. J. Stanley, W4RDG, asks, “My friends and I have been trying to apply crackle-finish paint to aluminum and steel panels, but with unsatisfactory results. Do you know of any method for producing a high-quality crackle-paint finish that does not require the use of expensive equipment?”
AGetting a good crackle finish is a two-step process with an
interesting twist:
- Spray with metal with a thin coating of zinc chromate primer. Apply the yellowish primer in an almost transparent layer and allow it to dry for at least an hour.
- Buy or borrow an infrared heat lamp for the next step. Spray on the crackle finish paint, following the instructions on the can. Position the lamp about 2 feet from the painted surface and apply heat for 2 to 3 minutes. The paint should start to crinkle right before your eyes. Be careful not to overheat the metal, though.
This technique takes some practice to perfect. I’d suggest that you experiment on metal scraps until you get the hang of it.
From QST March 2000
Q Daryl, W4DAI, asks, “I have just acquired a used aluminum HF-vertical antenna. What is the best way to clean it up for operation?”
A You didn’t say if your antenna has traps. If so, they should be cleaned with a mild detergent solution. Any stubborn insect residue can be cleaned with common alcohol. Of course, be careful not to get anything inside the traps themselves.
The aluminum portions can be made to look like new with a product called NevrDull. It is available at hardware and home improvement stores, and one can will last many, many years. It’s probably the best stuff I’ve found for polishing metal of any kind. (No, the Doctor doesn’t own stock in NevrDull and the company is not a QST advertiser!)From QST December 1999
