MTFCA Forum

I primed and final coated the springs for my 1927 coupe. Today, I applied Slip-Plate to the entire bottom of each leaf (except the bottom leaf) of the front spring. I have not decided whether or not to coat the top of each leaf.

I reviewed earlier posts about lubricating springs and found that some say to coat just the bottom and others say coat both sides. I thought I would just raise this question again before making a decision.

Comments?

Before doing this, make sure you have the correct tempered square headed center bolt for the spring. I would coat both sides and immediately assemble the spring leafs together and tighten the leafs together tightly. Any excess slip paint will squeeze out from between the leafs. Take a rag dampened with mineral spirits (not lacquer thinner) and wipe off any that has squeezed out. Don’t soak the rag. Too much will penetrate the leafs and keep the slip paint from curing. Use only enough the wipe off the front and back faces of the spring. Keep wiping until all excess slip paint has been cleaned from the front and back of the assembled spring. Jim Patrick

Jim, I think that assembling wet is antithetical to the product's designed application. Being that it is a dry-film lubricant, I cannot envision what benefit is derived from a wet assembly? I'd tend to believe that it would glue everything together and simply shear off of one surface or the other when flexed rather than remain adhered to both pieces and slide past each other. Hidden away inside an assembled spring, I suppose what we don't know, can't hurt us, but I really cannot envision a benefit to it.

My first experience with the stuff was in industry, coating a stainless shaft which had hardened and polished plain bearings rotating around it at very low surface speeds. It was wonderful in that application. I used it much later on my "T" springs long before I ever heard of anyone else using it for that...and always as a dried surface prior to assembly. In any event, a "T" really responds well to its use.

That makes sense Scott. Thank you for the correction. I think Bruce has already coated one side of each leaf. Do you think it should be coated on both sides? Once cured, how easy or difficult is it to remove the cured slip paint that was accidentally over painted onto the edges of the leafs? Jim Patrick

Hey there Jim...I cannot recall how easy or difficult it was to remove...I don't remember even attempting it. I simply used the blended wear pattern left on the top of each leaf to paint "up to" and a little past the wear pattern and then once cured, I masked the black paint and brushed on the slip paint, letting the masking keep it "inside the lines". I also burnished the dried slip paint with a wooden paint stirrer...a little flourish which was mandatory on our bearing work and probably overkill on the springs but it really did make a difference when testing for "slipperiness" with the back of a thumb-nail. With the exception of the main leaf, I coated the entire bottom of each leaf and the tops as described.

I think no matter how it is done, it is a great improvement over anything else.

I suppose any over-paint of slip paint can be removed from the face of each side of the assembled spring with a light rubbing of Meguiar’s rubbing compound to bring the edges back to their glossy black finish. Jim Patrick

Did my new front springs with Slip Plate on both contact surfaces, then painted over the assembled stack. If a show car I would mask off to 1/4” of each leaf, otherwise that hard graphite paint will fold over the edges and it has to be scraped off, really sticks. As it is slippery, even sandpaper get clogged fast.

My T is a tour car, here is view after about 1000 miles on the new painted front spring. One can see traces on the edges of the shiny graphite. Sure rides better!

Scott, Please explain what "burnishing" does to the Slip-Plate. In addition to making it "slipper", does it improve adhesion?

Burnishing is not at all necessary for our springs.

When we did it for NASA, burnishing removed the "fluff" off of the surface so as to not allow particulate to bind in the extremely small clearances we were dealing with. I only mentioned it out of interest's sake and don't want to mislead anyone into thinking it is necessary for our purposes in the hobby. We were measuring friction in dyne-cm (imagine the force you might apply against something with an broom straw held in a tweezer) and burnishing enhanced the slipperiness of it but we are dealing in huge forces when it comes to auto springs and no differences could ever be detected regardless of post application processing.

the fact that you're using it will provide great benefits to ride quality and that's all you are worried about

When I did my front spring I did both sides (except for the bottom leaf. then let them dry Instructions say at least 24 hours and then burnished the springs while waiting for the new parts to come in. In all the springs had about 4 days to "cure" before being assembled.

There should not be any paint on the leafs before coating with slip plate. The paint defeats the reason for using slip paint. Dry they shouldn't need any burnishing; spring action will do that quick enough.
When you are all done, don't forget to stake the end of the bolt to keep from turning off, same as when you do wood wheels.