To Paint or To Grease… That is The Question….

[OverEasy]

Hi All!

As I refurbish my boat trailer replacing the badly rusted nuts and bolts I’ve come to the dual axle leaf springs.
After saying good bye to the heavily rusted original leaf springs (~10 year old) I’ve also said good bye to about $500 to get the replacements. That’s a lot considering that six or seven months ago the same set cost less than $400… a whopping 20%+ increase!!!
Sheeze! And they aren’t even gold plated!

I don’t know about others wallets but mine fought back when it came time to pay up!
A real knock down drag out battle it was too!


They came with a light layer of thin paint but seemed that occurred after they were assembled.
Given the investment I’d like the new ones to last longer than the old ones with our salt water / fresh water launching and the damp humid weather we have that contributed to the degradation of the old springs to rusting.

There are a couple schools of thought on this …
- Leave them alone and us as is
- Paint them
- Grease them

I don’t know what the optimal solution is but I figured that a couple coats of rust preventative paint couldn’t do much harm.
To that end I mixed up some 50/50 Rustoleum gloss black paint with mineral spirits to allow it to creep/wick into and between the leaves.
After two through coatings I finished up with a full strength through finish layer coat.

I suspect that the flexing and relative movement will scrap away and or flake the paint off with usage.
I’m hoping it will at least slow it down …. I’ll probably have to repeat this painting more likely than not.

I’ve heard of some folks greasing their springs with a silicone dielectric grease but I’d have thought that would only attract and hold dirt, dust and sand.

Leaving them plain would just get me to the same place of rusted flaking springs.

Anybody here have any experiences or thoughts or suggestions on this?

Best Regards,
Over Easy

[Starscream]

Sorry I can't help with saltwater questions. I do feel for you saltwater guys, though.

Here's a photo of my 2014 black-steel trailer after countless freshwater dunkings. I'm afraid of what's going to happen to it after our Bahamas attempt this winter.

[Stickinthemud57]

A popular pre-treatment for painting rusting surfaces is phosphoric acid (Ospho), available at any good paint store and maybe a big box? It reacts chemically with the rust creating a solid surface to which paint can be applied. I have used it with good results.

The only question in my mind is whether the flexing of the leaf springs will affect its effectiveness (and that of the paint, for that matter). Perhaps others have tried it and have some info to add?

Applying grease might be better since it flexes and won't flake off.

[beechkingd]

IMO the best solution would be to apply black Fluid Film AS11B to the entire trailer. I've never done it to a trailer but it would be the best solution to save a trailer and all the components on it from rusting further.

[OverEasy]

That is a nice looking trailer StarScream!
I’ve always liked the look and paint color options of a plain steel trailer for fresh water use.
As we do both fresh and salt we were fortunate enough to have adopted Over Easy with a galvanized dual axle one.
It’s just the nuts and bolts along with the plain steel springs fortunately that have degraded even though we’ve tried to flush off with fresh tap water after dipping into salt water. I’ve even been spraying the old springs with WD40 twice a year.
Would the condition have been worse if I hadn’t? Should I have used something other than WD40? Heck, I dunno?……

Down here near the coast almost all the trailers are either galvanized or aluminum.
The few plain steel painted boat trailers are generally not aging well.

The times I’ve been able to ask and listen to locals about their trailers has informed me that few ever really travel long distances and are backyard to ramp trips which is sorta expected. Almost no one around here does anything to their spring except maybe rinse them and watch them disappear into rust… except the annual spray with WD40 if at all. All have had varying issues with the springs degrading but have been “good-n-nuff” to survive these short trips. As we travel North<<—>>South with each direction being between 1000-to-1500 miles on highways I just can’t in good consciousness settle for “good-n-nuff”. If I was just local on surface streets or boat yard then maybe… but probably not ( remnant professional type a personality ).

I have heard of people with plain steel trailers having had the sealed box beam type trailers drilling holes and flooding the interior space with motor oil for a couple days and then draining before installing seal plugs. That’s not really a bad idea perse but could be kinda interesting if/when one does a weld repair….

I’m leery of sealed frames as they can have pin holes and eventually suck in water when a hot trailer is immersed in colder water and that moisture gets trapped. Id prefer that the interior can naturally drain and dry out.
Over Easy’s trailer frame is an open box HD galvanized style so no trapped spaces.

The issue with the bolts I’ve experienced seems th be directly related to the nuts used. They appear to have originally used bright zinc self locking (nylock) nuts. I suspect that the thin bright zinc coating just couldn't hold up. I also suspect that the nylock insert scraped away some of the bolt galvanizing at assembly as I would suspect factory assembly was done with rapid air impact wrenches. I’ve gone back with all HD galvanized using split lock washers and hand tightening.

Here’s where I am currently with the springs…

The old worn out springs looked like this:
One can see that the leaves are gapping away from each other and the considerable amount of rust scale.
This also shows that the smallest leaf has fractured with one section broken away. This was masked and captured by the bottom clamp plate.







Here are the new painted springs:
The leaves are tight to each other.



And here are the old & new alongside each other:
(Yes I was a bit heavy handed with the paint but it’s a trailer not art )


After all this fussing I’m hoping it makes a difference over time….
Que Sera Sera

Best Regards,
Over Easy