Surtronics, Inc.

Frequently Asked Questions

1) What is Anodizing and Electroplating?

Anodizing is a coating of aluminum oxide that is grown from the aluminum by passing an electrical current through an acid electrolyte bath in which the aluminum is immersed. The coating thickness and surface characteristics are tightly controlled to meet end product specifications. Aluminum oxide is an extremely hard material that approaches the hardness of a diamond. As a result, the aluminum oxide layer provides excellent wear and corrosion protection. Hard anodize is more expensive due to increased energy requirements associated with the process. Ending cost differences are dependent upon many variables in a given order. For example: part size, racking instructions, packaging, etc.

Electroplating is a process by which metal in ionic form migrate from a positive to a negative electrode. An electrical current passing through the solution causes objects at the cathode to be coated by the metal in solution. The size, shape, and weight of the objects being plated determine how they will be plated. Electroplating is done to protect, beautify, insulate or increase the corrosion resistance, conductivity, or solderability of metal objects. It demands as much skill as any modern endeavor. Platers immerse objects into a variety of chemical baths in order to change their surface condition. Regardless of the finish being applied, the parts must be "surgically" clean.

2) What is the difference between an electrolytic & an electroless bath?

Unlike conventional electrolytic nickel, no electrical current is required for deposition of Electroless Nickel. The electroless bath provides a deposit that follows all contours of the substrate exactly, without building up at the edges and corners. A sharp edge receives the same thickness of deposit as does an internal diameter.

3) What size parts can you handle?

By finish:

Anodize Type I, II, & III: 12 foot
Aluminum Yellow: 12 foot
Tin (bright): 12 foot
Zinc: 8 foot
All others approximately: 32 inches max

4) What information is required on a purchase order for finishing?

We request that you reference the finishing process and any applicable specifications. We also require the coating thickness, alloy and temper of the substrate, and whether any supplementary treatment is required. (baking, etc.)

5) What information is required to quote an aluminum requirement?

Please specify the alloy, temper, quantity, and size, including any tolerances that may be applicable. We also need to know if there are any applicable military or commercial specifications.

6) How do you measure plating thickness of plating on my parts?

We use x-ray fluorescence measuring devices that use a beam to find the base metal and determine the thickness of the top coat. It has a very accurate result and is reliable. There is of course some margin of error when you are dealing in micro inches/meters but this can be overcome with proper calibration and maintenance. 

7) Can you plate on Aluminum?

Yes we sure can! We do have the capability of plating Aluminum and then placing any finish that we plate directly over that finish. 

8) What is rack and barrel plating?

There are two common ways to handle parts for plating. Rack plated objects are wired or hung individually on a plating rack. Barrel plated objects are placed as a bulk in a cylinder and processed together. Items that are hand finished, or are likely to nest or tangle usually need to be rack plated. Items that have been mechanically finished (tumbled) can usually be barrel plating.

9) Will plating "fill-in" scratches in the surface or pits due to casting porosity?

Plating does not fill small defects on the surface the way that paint flows and covers or levels the surface. The deposited metal follows the contours of the surface exactly because it is usually more reflective after plating the scratches and pits become more apparent.

10) What is the lead time?

We ship out most orders within 5 to 7 business days after receiving them. New accounts that require process development or extremely large orders may take longer.