Tumbler/Vibratory Polishing valve springs

[ijames]

Why not bead blast the springs with your walnut hulls to remove the paint and possibly give a mild surface polish? Should be able to do a good job on the inside of the coils, too.

[digger]

WPC is The stuff they treat bearings with. It's micro shot blasting. Spring manufacturers already use multi stage shot blasting so perhaps WPC is no better

[BOOT]

I'd try blasting if I had a blast-cabinet and someday I will but I also like the idea that ultra sonic cleaner might get w/e is embedded between the top n bottom coils?

[Kevin Johnson]

I'd try blasting if I had a blast-cabinet and someday I will but I also like the idea that ultra sonic cleaner might get w/e is embedded between the top n bottom coils?

Methylene chloride was the kicker in mil-spec aviation paint strippers. Nasty stuff. Back in Detroit I would keep an ultrasonic bath heater on with tall Pyrex labware that served to condense/recirculate a bath of it.

I would drop in a crown full of polishing compound and POW --- it was clean. OSHA-no-no now.

You might try a Variac with your HF device. I have one and IIRC it has an on/off switch. Varying the volts might set up a better flow pattern of the particular media you choose.

[David Redszus]

https://performancetechnician.com/pdf/2 ... prings.pdf

At the tire pump or carb fuel inlet and in most technical disciplines "pressure" is used when considering the area to which a force is applied.

In most of our literature "pressure" is also used when talking about the force exerted by a spring when compressed.
That misuse is kind of unfortunate, and probably causes either a chuckle or some heartburn when read or heard by folks with more formal technical backgrounds or training.

But usually in the cam catalogs the "error" stops at the word pressure, and the spring's force is correctly described as just pounds.

The article in the original post is a little loose with its use of "terms and definitions," adding the per-square-inch where it really does not belong.

Seat or open pressure
The pressure in pounds per square inch of
the installed spring with the valve on the seat.

Nose or open pressure
The pressure in pounds per square inch with
the valve in the fully open position.

Spring rate
The amount of weight needed to compress a
spring one inch, rated in pounds per square inch.

Spring rating
Spring load in pounds per square inch at
both the open and closed position. Usually
displayed as a range, for example “125#-425#.”

Dan is absolutely right and the article is wrong.
The ability of a spring to resist movement is called force, never pressure; the units are lbs/in, not lbs/sqin.

There is one exception: spring stress, which is a measure of force divided by wire area, (psi).

The best preparation for a spring is shot peening. It provides a stressed surface and increased resistance to
breakage. However, there are many grades of shot peening based on shot size and air pressure.

[Kevin Johnson]

I would be very hesitant to shot peen a spring -- the reason being that without specialized equipment and PRACTICE lots of PRACTICE, you'll be likely to introduce uneven stress in the coils -- possibly even cause it to no longer be normal to the spring pad (tilted or warped -- very bad). Try shot peening some thin metal and you will see how it will warp/distort the object.

[BOOT]

Also why blasting would prob be my last resort, I have one of those roll around blasters that warped a set of sheet metal valve covers like nothing. Course a smaller blaster might not.

[David Redszus]

I would be very hesitant to shot peen a spring -- the reason being that without specialized equipment and PRACTICE lots of PRACTICE, you'll be likely to introduce uneven stress in the coils -- possibly even cause it to no longer be normal to the spring pad (tilted or warped -- very bad). Try shot peening some thin metal and you will see how it will warp/distort the object.

Over the years, I have shot peened many hundreds of springs without a single failure. It is a standard procedure at the OE level to remove scale, surface rust, remove small imperfections and strengthen the surface. Shot peening will increase service life to a greater extent than any other surface treatment.
All high performance springs should be carefully inspected for surface defects (the most common cause of failure) and then shot peened.

A search of the SAE data base will produce numerous white papers regarding the benefits and procedures
for proper shot peening.

Find a shop that specializes in metal finishing and has the proper materials and equipment for the job.

Shot peening is also used on rods and other stressed components.

[Kevin Johnson]

My comment was a cautionary one -- I did go out and purchase a large shot blasting grade cabinet and steel shot and shot peened items. Make sure that your system has an excellent air drying (water removal) system and promptly remove and store the steel shot in a sealed container.

Practice a whole bunch on scrap springs, perform the measurements or let a shop with the proper equipment do so.

I have highlighted what I was referring to -- a valve spring that no longer sits "normal" (90 degrees upright or "squarely") will side load your valve guides.




https://www.shotpeener.com/library/pdf/1982016.pdf

Side Effects of Peening
Shot peening can have an effect on the size and/or mechanical properties of a spring. Because of the residual tensile stresses remaining from the forming operation, which are changed to compressive as a result of the peening operation, the spring may tend to undergo a slight dimensional change. For example, a coil spring will tend to grow slightly. This will mainly occur in thin-section material and small diameter wire. These changes are minor and generally do not represent a problem. However, if the spring has a very critical dimensional tolerance, compensation can be made in the manufacturing process to make allowance for the change in dimension. After shot peening, a minor reduction in spring rate may be noticed. Again, it will be a minor change and usually not of concern, but can be compensated for in the forming of the spring. Another side effect is an increased tendency of the spring to take a permanent set due to the stresses produced by the shot peening. Consequently, it is common practice to heat springs after the peening process. This is a low-temperature baking process as compared to the higher temperature stress-relief process used after forming or coiling. It is a common practice to bake the springs at 400-450°F for a period of at least 30 min. Temperatures in this range will not have an appreciable effect on the peening stresses, but will greatly affect the set characteristics, This low temperature heating will also tend to counteract any minor dimensional changes which may have taken place as a result of the peening process.

[BOOT]

Ok so I bought an ultrasonic cleaner and tried it with Mineral spirits but nada. Then I decided to try paint strippers since the ultrasonic would maybe remove the loosened paint. BUT I never tried the stuff because I found other alternative cleaners that worked just as well. Long story short the paint is 100% off and if you wanna check out the vid here it is.

[ijames]

Glad you found a few things that work. I have a couple of suggestions for you on how to best use the ultrasonic cleaner. First, the problem with putting solvents like mineral spirits directly into the tank is that now you have to be sure the drain valve and your tubing will stand up to them, and that tank holds a lot of solvent. Also, putting your items in the tank means that all the sludge and debris from cleaning will have to be scrubbed out of the tank and may clog the drain valve. For big items like a cylinder head in a very large ultrasonic cleaner you don't have a choice, but with a smaller unit like yours and working with small items like the valve springs I think there is a better way. Put the valve springs in your glass jars along with your solvent, fill the ultrasonic cleaner with clean water, and put the jars in the wire basket so they are not sitting directly on the bottom of the tank. Of course adjust the tank water level and the solvent level in the jars so the jars don't fill with water or float away. You can put lids on if you want to suppress evaporation but don't tighten them or they will pressurize as they heat up. Space them out so the jars don't vibrate against each other. You lose a tiny bit of the ultrasonic power but you gain a bunch of convenience and you use much less of the solvent in the jars. You can also use plastic bowls or cups in the ultrasonic cleaner if they will stand up to your solvent, but I think you lose a bit more cleaning power than the glass jars. Finally, go ahead and put the valve springs in the jars with your paint removers in the ultrasonic cleaner - heat is always a good thing for speeding up the paint removal and the ultrasonic action may also help. Go ahead and try your four choices that way. I don't know but maybe the simple green or brake fluid will work fast enough and if they are cheaper than the others you might be able to use them, or not (the fun of science is exploring). Keep the same water in the ultrasonic cleaner, with a lid on to keep dust out, and just change it as needed.

A couple of little things. Methylene is pronounced as meth (like crystal meth) uh (like duh ) lene (like lean meat). You basically had it right but kind of trailed off the end like you weren't sure. Also you said that valve springs were made of cast iron but they are made of various steel alloys. Nice job on the video.

[BOOT]

1st Thx for the tips, I did my homework and found most of what you suggest. The cheap hose I plan to replace eventually when it degrades enough(also why a hose clamp is a good idea) and I flush & wipe down the machine after I'm done with each setup but it's just a cheap model. I didn't bother with the jars inside the ultrasonic cause they worked good enough and I didn't need it done super fast(just over an hr the ZEP would be fast enough w/o the machine) and most the sludge stayed in the jars. Plus in my research I was unsure if I needed beaker quality glass as some said certain kinds will break in an ultrasonic cleaner, prob not this one cause it's kinda weak. Good tip on the lids I wondered that, a small vent hole would prob work well, long as rem it's there and don't spill later.

If I didn't plan to use the Ultrasonic cleaner for other stuff it would of been a waste but I wanted a cheap one to try out anyway. Think I said steel and cast iron would be safe with lye based cleaners. Thanks for your feedback!