Slag on Springs??

Islandkent · Apr 3, 2019

Hi guys. Was just wondering if anybody ever seen this before. Took apart my springs on Saturday and epoxy primed them. Seen a bit of something on them but didn't really notice anything until we put the first coat on them yesterday. My body man let them dry and I went out to see them today. We took the DA to the worst section to see if it was a reaction or something. When we got down to bare metal you could see it. It looks like slag when the springs were made?? Any Ideas? Would there be a way to fix it? Sure most of it is hidden but just wondering if high build primer would work on a spring? I was kind of wondering about the pitting also from rust? I'm kind of disappointed with them.
Thought I would bend your ear.
Here is a few shots of what I'm talking about. I forgot to mention I did sandblast them first.

Rob'68Net · Apr 3, 2019

You could technically use high build primer, as long as it is made to bond direct to bare metal. Otherwise, I would recommend you to use epoxy primer on the bare metal, and then move on to high build primer. Another option would be to use PPG's product AUE. This is an acrylic urethane commercial coating. It is direct to bare metal (no primer needed) and is a bit thicker paint (will hide more imperfections).

Islandkent · Apr 3, 2019

Yep Blasted them and put the epoxy on Saturday. This is right in the metal. Seems the only way to get it off would be to grind/sand them down. The picture above is after we took the dual action sander to the spring to remove the paint and epoxy. Would take a lot to finish smooth. Oh well looks like a new pair of springs or live with it. Probably live with it till I get her all painted and back together.
I was just wondering if anybody ever seen this before? Thanks for the reply guys!
Sandblasting/Epoxy Priming

Fran Blacker · Apr 3, 2019

If the base metal went through a hot roll rolling mill the stag could be chips of slag rolled in.
When I say hot rolled means the metal was red hot when rolled to finished thickness. Worked in rolling mills 38 years and that what it looks like.

Mocajava · Apr 3, 2019

I agree with Fran and that is mill scale formed during the heat treat process, common on tempered steel. A torch ran across it will pop a large percentage off but the grinder will do the same removal, just that the operator may dig in a little more than necessary. I used to see that a lot on 4140, 8620 and 4130 sheets up to 6" thick when I ran a big track torch. Unsightly and will form rust after a period of time between scale and base metal. You did well to remove it.

Islandkent · Apr 3, 2019

Bingo Fran! That's exactly what it looks like. Thanks. Must be more examples than just my poor springs though. When we took the DA to it, It looked like it was right in the steel. Looked? It is right in the steel. Not all the leafs just a few. That picture up above is the worst example. Thanks again.
Yes unsightly is right. I'm going to wait and see what they look like once I put them back together. I'm still on the fence on what to do yet. Time will tell I guess. Thanks for the reply Mocajava.

Lefty71 · Apr 4, 2019

Wouldn't torch or maybe even grinding potentially damage the spring though??

moparnation74 · Apr 4, 2019

That’s the worst I have seen on springs but I have seen it on springs......

Keep in mind the temperature range of the paint you use. If you drive the car enough they generate fair amount of heat. The wrong paint with burn off the sheen slowly and will create micro holes exposing bare metal and thus leading to rusty springs.....

Islandkent · Apr 4, 2019

Leave it to me to have the "Worst I've ever seen" spring slag! lol lol

The story of my life! lol I did the research also... She is a Monday car. lol
Yeah I used proper automotive epoxy and proper paint with the hardener and actuator and a bit of flex agent the good stuff. Good service out of this paint.
I was thinking and ruled out the torch solution. Even the grinding is out of the picture also. I going to the shop after I right this to pick them up. Really hard already(paint) so I will see how much of this stuff is showing once I put them together in a trial fit. I have way too much money in these original springs already. Blasting, epoxy, paint, rebuild kit, bushings. What's another $400. If I could get away with that.
That's for the replies Lefty and moparnation. At least I found out that this has been seen before.

Fran Blacker · Apr 4, 2019

If someone is crawling underneath your car telling you the springs are ugly they have a problem.

Islandkent · Apr 4, 2019

Amen Fran. Amen.

Slag on Springs??

Islandkent

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Rob'68Net

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Islandkent

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Fran Blacker

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Mocajava

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Islandkent

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Lefty71

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moparnation74

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Islandkent

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Fran Blacker

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Islandkent

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