Parkerizing is'nt rocket science,but it does require attention to detail to have a good outcome. I've done a lot of it and would offer the following bits of advice.
-use a kit instead of playing with DIY "strange brews". Chemicals and proportions thereof in the kit are tested and are of known proportions. Also, the residue can be salvaged and re-used.
-follow the manufacturer's instructions,especially on temps,timings,parkerizing vessels and metal prep.
-be scrupulously attentive to oil and grease removal(incl fingerprints) as these will contaminate the solution and yield a poor result.
-disassemble all parts and blast surfaces. Surface blasting creates a clean, active steel surface for the park to work on and will produce a uniform result.
-get the blasted parts into the park solution ASAP to minimize oxidization(rusting).
-pre-heat parts to 180-200 deg F after blasting and prior to immersion. The hot surface seems even more reactive with the chemical and pre-heating will avoid lowering the temp of the solution.
-after parking is done,remove parts and get into a hot water rinse ASAP followed by a stopping agent and oil bath. I keep parts wet with oil for about a week which seems to help curing and adds to durability and appearance.
-monitor temp of solution using a candy thermometer. Use stainless steel tongs to handle parts in/out of solution and to turn parts while in solution.
-one of the best vessels to use is a large oblong crock pot. The ceramic pot is non-reactive to the park and cleans up easily. The pot will also bring solution up to the required temp and hold it there. A crock pot will do all parts of a rifle,less barrel and other long components like a Garand op rod and is economical with solution. If wind or cool temp are a problem,you can place the crock pot in an enclosure and insulate with metal faced bubble insulation to get the temp right. Keep the pot covered to maintain temp amd minimize evaporation. N.B. This is now your dedicated park pot. Do not use it for cooking. Cheap is good,but dumb is dumb!!
-once solution cools,filter thru a coffee filter into a clean widow washer anti-freeze ctnr,label and save for re-use.
-park is an acid based solution,so always work outdoors with good ventilation. Wear rubber boots and gloves and keep a large pail of water handy to rinse off accidental spills. The solution will dis-color concrete,so take precautions like placing the pot on a sheet of plywood. Do not do this indoors on a kitchen stove or use a microwave to heat solution.
-you can select a kit to produce the type of color you want. A manganese based park will give a nice black finish (my preference) while a zinc based solution yields a grey finish. You will find that parts will exhibit different shades of color depending on the steel in them. Softer steels,like those in barrels,bands and buttplates tend to come out a bit darker. The same manganese park solution will yield a deep black color on Springfield and Breda Garand receivers and produce a somewhat lighter color on IHC and WRA receivers(except for WRA receivers which were annealed by molten lead immersion which show a much darker contrast for the annealed portion).
I still love my welfare park jobs. I'm so proud of them!
