Tips and Tricks

[tomg552001]

I'd also like to to this topic. For me, the smell of curing powder for too long of a period gives me a bad headache. If this happens to any of you guys, or the smell makes you feel sick at all pick up a particulate dust mask with a activated carbon layer. It helps reduce if not kill the smell, and lets me continue my day without a violent headache.

[non-stick]

From time to time maybe you've wondered what colours go with what. Perhaps, somebody has asked you in confidence as a powder coater "what do you think, you've been doing this a while" only to find yourself as confused as they are about available choices. The link below explains (sometimes in great boring detail) how colours go with one another and how to effectively use the color wheel to it's fullest. Who knows... you may just surprise yourself with odd recommendations of an orange ochre with a linen taupe! lol. Anyways.... here's the link and I hope you not only learn something useful from it, but it makes your decision in exactly which powder to buy from here easier for you...... Russ

http://www.hypermaths.org/quadibloc/other/colint.htm

[non-stick]

As time goes by, some of you hobbyists will be doing things for your friends and accepting "donations" to your hobby fund (assuming you havn't done so already,lol). I have no idea what you guys are charging to compete with the "pro's".... but here may be some simple guide-lines to help you out and get that winning bid for your parts.

Professionally..... we work on a 6.6 hour day. By the time the worker gets in and does his morning routine of talking to his buddies,has a break in the mid-morning, another for lunch, and then another at mid-day and drags his or her backside to the timeclock... it works out to 6.6 workable hours in a full shift. Now... with that said, the business owner has to get the most production of of the worker and price accordingly to make up for labor/taxes/insurance/etc. Assuming the standard powder coater makes $15 dollars an hour, we double that for taxation and add another 10 for insurances (worker's compensation and health). This equals to $40 dollars. *MOST* bosses pad the amount by 75% to make up for dealing with paperwork and lost time,energy expense, etc therefore leaving us with a $75 dollar per hour labor rate. This is a very general figure as the higher salaries go and more technical research one warrants... the higher the fees go. So technically speaking... the labor for an average worker looks something like this
8hrs X $75 per hr = $600 dollars USD.
Mind you.... to break even the boss has to charge for at least $420.75 (6.6 workable hrs @ $75 - 15% (for profit) to make up for ultimate loss). Therefore leaving us at the mark of $52.59 per hour that the boss HAS TO make in order to do the job at cost. This is a good thing for you because you are not at this level. Your structure may look like this......

1 workable hour @ $15 dollars (under the table tax free) plus energy and materials cost ($25 dollars per hour) = $40 dollars per hour. Therefore a saving of 12.59 per hour that the "pro's" can't even come close to. When compounded by the day, it equals a $100.72 dollar loss for the day, and $503.60 dollar loss for the week.... per worker! Most small job shops have an average of 6 workers so that leaves us at $3021.60. See how much you look better now? Let's use this in a "real world" example now, shall we?

Instead of my infamous "widget"... we'll use a set of valve covers from a small block Chrysler product ( just because I don't like the groans from my widgets,lol).
Typical "over-all" work hours are broken down like this.....

15 Minutes receiving of parts
1 Hr sandblast and prep (inludes hanging and cleaning)
30 Minutes coating
1 Hr Oven time
15 Minutes wrapping and packaging.

Of course.... the more you fit in an oven,do all at once,etc... the more you gain. But that's understood.Also... the more you complete this process, the smaller the time estimates will be for you as a worker.

This totals 3 labor hours. For the typical powder coating shop, the amount may be close to $225 dollars ( I know some pro's charge less. We're using textbook logic here). For the "professional hobbyist" however... your fees are approximately $120 dollars. The goal here is this.... to cover for your time, materials, energy useage and foreseeable expenses in one billable hour,$40 is more than fair. For any of you actually past the "professional hobbyist" stage, if your pricing is much lower, you're going to lose. I assure you of this. Sit down and do the math! For the professional hobbyist... this is VERY close to where you need to be. Imagine the part in hand and "pretend" you are sandblasting it. How long did it realistically take? Now pretend to powder coat it? Add that to your time.... imaginary time from a dead-stop in the oven? Factor that in as well. Packaging, and recieving time? it all adds up. Total it all out and multiply by the $40 per hour rule. Professionals will almost invariably try to get an "oven full" of parts to bring the cost down. As well they should! Therefore bringing the process time down by maybe a half hour or so. Volume orders can also be adjusted accordingly. (some as much by 40%!). The simple point is.... in order for the "professional hobbyist" to compete, one must realistically approach the project with time in mind. If you do too many "favors", you will no doubt go broke very quickly. Take your time, get a feel for where you can cut corners (hobbyist and pro alike) and price accordingly. Hope that helps somebody out there.... Russ

[non-stick]

Often times we may be up against a wall in what compressor to choose for our needs. Some hobbyists may require only a 2 HP 10 gallon compressor while others have greater needs for a 50 HP unit complete with air dryers and aftercoolers. The choices inbetween the two are astounding. Rotary screw, piston type,oil-less..... it's enough to make your head spin sometimes. Let's focus on the two main types of compressors first, shall we?

Rotary Screw ~ Traditionally cooled and lubricated through glycol, this compressor offers the ability to create massive amounts of compressed air and a rapid response to loss of pressure. The system basically works by taking two rotating shaft assemblies and forcing air via means of constant flux of negative space between the "pattern" or design of the shaft. Another form of this method is seen on "blowers" for automotive use. While they may take slightly more power to produce the volume of air that it's cousin the piston style does... it makes up for it's appetite with noise reduction and low serviceability.

Reciprocating Piston ~ You've no doubt seen this compressor everywhere, no doubt. The true workhorse of the industry. This design most resembles that of your common automotive engine in many ways. A motor spins the crankshaft of the air end. One piston draws air down through valves while the other exhausts it into a tank reserved for when you need compressed air. Forever runninf in this fashion, air is moved along at a hefty pace from the intake to the exhaust of the "compressor" until a certain pressure is achieved. Once said pressure is achieved the limit switch tells the elcetric motor to turn off and stop the process. No doubt there are varying types of this compressor in use all over the world, but this is the basic principal of the machine. What the resiprocator lacks in style and grace that it's cousin the rotary screw has, it makes up in longevity. It's not uncommon to see this style of machine in use for well over 3 decades with simple rebuilds along the way. Slightly more noisy, this compressor is like the enrgizer bunny. It keeps going and going and going.....

With that said, here are some handy rules for estimating when looking for a compressor:
1. Air compressors are normally rated to deliver 4 to 5 CFM per horsepower at 100 PSIG discharge pressure.( non 110V estimates. Lower voltage is approx 1-2 CFM per HP)
2. Depending on the the size of the system, compressed air costs about 25 to 42 cents per thousand cubic feet of free air ingested by the compressor (including operating and maintenance costs).
3. A 50 horsepower compressor rejects approximately 126,000 BTU per hour for heat recovery.( they make heat. adjust accordingly for your HP needs)
4. Motor amperage draw: 1 Phase 115V - 10 Amps per HP
230V - 5 Amps per HP
3 Phase 230V - 2.50 Amps per HP
460V - 1.25 Amps per HP
In the general "6 levels of compressed air quality", powder coaters generally fall in the middle at level 3. That is to say you will need : compressor, refridgerated compressed air dryer and an oil removal filter. This system removes 99.999% of oil aerosols and any solid particles larger than .025 microns.

A good general rule of thumb to follow when researching your needs for a compressor is as stated : (requirements now + 20% growth) + 20% demand factor. That is to say..... if you need 25CFM (cubic feet per minute) now to supply your needs, add 5CFM for a future growth and 6 CFM for demand of draw. This equals 36 CFM requirement MINUMUM when shopping around for a new compressor (again, these numbers are used for an example purpose only. Your needs will be different). It's often a common mistake that we see something "on sale" only to find out perhaps a year down the road that we should have spent the extra money because you can't operate all of your equipment now that you've expanded. Or even worse.... you can't powder coat when somebody is blasting,therefore creating a loss of billable hours within your facility.

After all is said and done, it boils down to "do your homework". A compressor is a tool used to make money with, bottom line. If you buy cheaply made.... it will invaruiably break down on you at the worst possibly moment and you'll have to repair or re-purchase anyways. I suggest you calculate for your needs and abilities and then for your budget. Shop around. Wait for the sale. Ask that friend of your what he's doing with that old compressor he never seems to use . I hope that helped somebody out there in your decision to purchase a machine that will service your needs for quite a while to come. ..... Russ

[etyrrany]

Sometimes we're faced with powder coating projects/jobs that involve heavily rusted items. This was the case with my most recent project. I wanted to powder coat a pair of steel rear calipers for a Mazda that have been oxidizing for almost 10 years. The rust was so heavy that you could knock it off with a screwdriver in some parts. I tried blasting them with aluminum oxide but after about 10 minutes I seen that the progress was not worth my effort. While glancing through the home shop/hobby magazines during a chance visit to a local Chapters that day provided a solution. Removing rust by simple low volt electrolysis. Here I will detail my setup and provide a couple links that show more setups.

My setup consisted of:

1. 5 gallon bucket
2. 2 sq.ft of ceramic tile lattice
3. Arm & Hammer Washing Soda
4. 6 Amp battery charger
5. 2 ft. of steel rod
6. 3 ft. of 12 gauge insulated copper wire

Steps in creating my setup:

I took the ceramic tile lattice (this stuff you can buy at the local hardware store and it is used to strengthen the cement base when laying floor tiles) and cut out a circular disc just smaller than the bottom of my bucket. Then I cut out a rectangular piece of lattice with a width smaller than the height of my bucket, about 2 inches shy of the bucket rim. The length was about 10% less than the circumference of the bucket. Than I proceeded to bend the rectangular piece of lattice around the circular disc I cut out earlier. What you want is a cylinder made out of the lattice that you can put in your bucket. I did this because the electrolysis works more of less on line of sight. This gives a good electrode as the surface area is large.

I then took a 3 ft. piece of wire and attached it to the lattice securely. I then put the lattice in my bucket.

I then proceeded to add about a tablespoon of Arm & Hammer Washing Soda to each gallon of water. If you put in a bit more it won’t hurt a thing. I then filled in with warm water and gave it a good stir to dissolve the Washing Soda.

I then took my caliper (aka. widget) and connected it with the other 3 ft. piece of wire. Sometimes it is very hard to get a good connection because the part is rusty so I had to grind some of the rust off to get a good connection.

I then immersed my item into the solution making sure that it did not touch the lattice anywhere. I stopped the part from dropping to the bottom by making three wraps of my wire around my steel rod. Once I was satisfied that my part was not touching the lattice anywhere I placed the steel rod across the bucket.

I then proceeded to connect the POSITIVE lead from the battery charger to the electrode, my lattice. The negative lead was connected to my part. The polarity is VERY IMPORTANT. If it is hooked up backwards (negative to electrode, positive to item) you will actually build more rust on it, it will oxidize even further and at a very increased rate!!! You will destroy you item!!!

I then proceeded to turn on the battery charger. If you have an Amp meter on your battery charger you can see how much current the electrolytic process is using. You can always test it with a multi meter. Almost all modern battery chargers will at least have a voltage indicator. If the voltage is extremely low you probably have a short circuit, you part is touching your electrode. Correct at once. My volt indicator was showing an average of 10 volts when I was doing my calipers. It might rise slightly as rust is removed and more metal is exposed to current flow. This process will generate oxygen and hydrogen, not a lot, but I would advise a well ventilated area. No smoking or open flames!!!

Overall I find this process very ingenious and satisfying. My calipers, of which there is a picture available in the album were immersed for about 6 hours. I was in a hurry and this is all the time I allotted my self so all the rust did not come off. If I had left the process overnight I believe that all of the rust would have been gone.

Maybe some of the plating/anodizing guys can recommend a better solution.

I include some links for more information and varying setups:

http://www.oldengine.org/members/billd/electrol.htm

http://www.stovebolt.com/techtips/ru..._derusting.htm

etyrrany

[non-stick]

I know this isn't a subject that we really havn't gone over that much, but I just wanted to key you all in on the importance of documenting "how" you do things around your coating shop. Everybody has thier own unique way of application of powder,sandblasting,masking,cure times and temps. This is all YOUR process. You know what works best for you. If you're anything like me and have 9 million other things going on in life, a notepad and pen are your best tools in coating to help you remember those important factoids that may be easily forgotten about when you come up against something that you've done before but are very tricky. Quite often I revisit old notes and papers of things that I've done in the past to gaurantee my results for the future. Let's face it.... we're all only human and human's don't have as good a memory as we'd like to believe. As some might attest on here, I like to know the whole process on paper as I'm doing it so I can reproduce results easily enough if they are successful. Also... if something went wrong, I can look at the paperwork to see where my errors are and not make the same mistake twice ( hopefully ). It only takes a minute to do and it's REALLY worth it's weight in gold in the future. A widget example if I may.....

I have a widget that I'd like to coat. The customer wants it blasted,cleaned,phosphated and coated with a base of bright red and a top coat of clear. The widget is made of stainless steel though. AHA! There's always a catch,right? Assuming I've done this before, I'll go back to my notes and follow the results that I've had success with and then repeat them knowing I have money in the bank. If not, I'll get out a scrap of paper and it will look something like this.

1) Mask widget with silicone plugs ( threaded holes ) and sandblast.
2) Sandblast black oxide at 90 PSI
3) remove masking and solvent wash in isopropyl alcohol with stiff brush
4) Hang and air dry for 45 minutes. Blow off with clean air @ 90 PSI.
5) Phosphate wash. 20 min in full solution ( Caswell p/n SSB370 )
6) Mask for coating. Silicone plugs and green tape ( Caswell p/n Prod #### and p/n pctape1)
7) Basecoat with red ( Caswell p/n PCP56022 ) cure 410F @ 16 minutes. Remove from oven and let "air quench" for 5 minutes.
8 ) Top coat with clear ( Caswell p/n PCP4444 ) cure 410F @ 16 minutes. Shut off oven and open door. Remove when cooled to room temp.
9) Unmask and trim.
10) end process.

That's basically what it looks like. This list tells me how I did it, where to get the materials to acheive the same results if need be and what my cure schedule was. Assuming you put this paper in a folder somewhere.... it doesn't matter if you need to go back to this "recipe" a week from now or 10 years from now. It's all the same and the results are still there. It also serves the purpose that if you missed a step you can see clearly against other results where you went wrong. We'll omit step number 3 for example's sake. You take the part out of the oven and there are bubbles all over it. Oops, what went wrong? Ahhhh... I can see we didn't degrease properly with a solvent to get the oils off and that's where I went wrong. Now I know better. See how that helps now?

Invest 3-4 dollars in some paper and pencils. Get yourself a nice 3-ringed binder or a student type "trapper keeper". Don't be afraid to scribble down ANYTHING that might pertain to what you are doing. If you have a digital camera, take pictures and print them out and staple the whole thing together if you wish. It's all in the name of consistant success. The more knowledge you have, even if it's on paper, the better you will be a coater in the long run. I gaurantee it. Hope that helps somebody out there.... Russ

[bzer1]

I'd like to add a little trick that I mentioned in another post here so hopefully it will help someone with booth cleanup and color changes.

I was admiring my handy work one day when I realized that it was going to be a royal pain to clean the excess powder from the inside of my booth. Even though it has a filter and fan, there would still be a pretty good amount of stray powder in the corners. I thought that I didn't want to waste too much powder so I didn't want to rely on a vacume, so I decided to use the closed circuit of the process to reclaim the powder. Now to get to the point... Electricity is your friend. I went to my local Home depot and picked up a plastic spackle tray... It's about 10" long and tapers down from 4" wide. At the bottom I put a piece of angle iron with a bolt attached. I used a jumper lead(wire with alligator clips) to complete the grounding circuit. The parts hang pretty high in my booth so the additional ground doesn't pull powder away from the parts. When the still charged powder falls to the bottom of the booth it's attracted to the grounded metal piece and sticks to it. When you finish coating you just disconnect the jumper and set the tray aside and let it discharge then do the rest of your clean up. A word of advice from someone who spent many years working in shops...Always clean up when you finish your job, you don't want to face a cleanup when you go to start your next job.

[Blademan]

Clean the suckers like you were cleaning a part....specially if your using a home type oven...strange things float around in hot air.....
lesson learned,,,hard way..

[BerkelUSA]

Originally Posted by Blademan

Clean the suckers like you were cleaning a part....specially if your using a home type oven...strange things float around in hot air.....
lesson learned,,,hard way..

Blade, Check out my Fiero (20 year old) upper A-arms.. 120-psi for 3 minutes each - Got sick of siphon, pot & cup blasters.. so mixed parts from them all and made my own.., Stumbled upon a way to blast that is like no other!, So stupid its FUNNY, But if you cant calibrate it correctly and know what to look for it doesnt work right..

Next is the oven as we turn rust into GOLD.. , A nice little 4'x 8' trailer that will be mobile.., Just got the fans for it today, But steel will need to wait until after Christmas (3-kids), CANT WAIT !

Anyone want some kids?

Regards, Rob in NH

[cdaeme]

I would first like to say I am in no way associated with Ammoman, Pablasters or Rob.

With that said I have dealt with Rob on several occasions lately all the way back to buying some hard to find ammo from him earlier in the year. I bought his plans for the PaBlaster and joined his Yahoo group for DIY'ers (Do It Yourself). He has an awesome group with some really ingenious ideas that apply to powder coating. He is very respected in his group I plan to build my on PaBlaster in the next couple weeks and I will post back how well it works.

I’m not trying to sound like a salesman for Rob but simply wanted to let the masses here know he is a good guy.


Jason
Auto-Cycle PC