Chainplates from grainger

[model 10]

Roloc disks work better than a floppy thing but you need to go to the 80 grit to get rid of the finish marks. This is how it will be. You should consider giving up on the sanding thing and just buff what you can and then clean them somehow. Some sort of acid (phosphoric maybe). The more you sand them the more scratches you are going to have. There were no scratches until you started sanding on them.

[VinnyVincent]

Terra Nova, Are you talking a mini bench grinder or angle grinder? I have a full size bench grinder and a 4.5" angle grinder. I can only find flap discs for the angle grinder.

So guy are you suggesting to just palm sand with 120, 220, 400, 800 then go to polishing and leave the tiny dots?

[VinnyVincent]

Honestly it seems pretty easy getting rid of the scratches from the previous grade of paper. It's the Million little holes from when the steel was made that im worried about...

So 80 grit disc, then 120, then back to the palm sander with the 220-800 grit, then polish?

[Cheechako]

Yeah, those "pits" are likely from the rolling process which embeds debris/slag into the surface.
The bar is rolled hot and often there is a final pass to net size as it cools down... introducing some cold work strength into it.
I'd say you are learning why some things like chainplates etc are so expensive. :>)


I have often tried to fix things that "are'nt broke" on boats and often wondered when I was done if I gained anything at all.


At this point you don't know if anything was bad with the originals right? You are not taking this boat offshore, but rather buying a bigger one later right?
Myself and many others on this forum have boxes of stuff we thought we needed, some of which was unused when we got in the middle of the project, stopped, took a deep breath and said "why am doing this?"


Just sayin.... take a breath.....

[Terra Nova]

If there are still holes, you haven't sanded enough.

A mini grinder is a small angle grinder.

[VinnyVincent]

I may go offshore with this boat, but no more that 10-20 miles on an extended weekend trip with a good weather window.

Mainly I just wanted to change them since I was vettingnew rigging. It seemed prudent to change all the pieces from top to bottom since i was already doing all the rigging.

I could just go to the polishing at this point, but I am wondering if half finished new pieces would be any better than the old ones. Honestly I kind of enjoy doing the work and learning new skills...I just need to know where to go from here to get the finish where I want it.
I came this far with it, no point in backing out now

[VinnyVincent]

Originally Posted by Terra Nova

If there are still holes, you haven't sanded enough.

A mini grinder is a small angle grinder.

So just switch to a 120 grit flap disc and see is that takes them out?


I was looking at the scotch brite roloc discs too but was not sure which to start with.

[Terra Nova]

Originally Posted by VinnyVincent

I may go offshore with this boat, but no more that 10-20 miles...

10-20 miles is offshore?

[VinnyVincent]

For me it is lol...galveston bay is pretty big, i get lots of sailing in around there, but have only taken my laser out into the gulf.

I'm trying to work this cheap boat I got into something I can depend on to take out into the gulf. It does take about five hours with good wind to get from my marina in clear lake out to the channel that leads to the gulf. This was actually the last major project before I take it into the gulf.

[VinnyVincent]

Anyways so Im a little confused because you guys originally said sanding with 80 grit was a bad idea, but now it seems I need to go down to 80 grit to remove the tool marks/imbedded contaminents?

Is it better to leave the contaminents and imperfections, or sand them off with 80 grit?

[Stumble]

It's better to not have to use 80 grit, but the contaminates have to come off. If you can get them with a higher grit then great, if not then go down to what you need. But be forwarned it is indicative of a lot more sanding in your future.

[Stumble]

Oh god something just occurred to me....

Please tell me you are starting with polished not mill stock flat bar? If you are starting with mill stock you have a god awful amount of work on your hands.

[VinnyVincent]

It's fresh off the mill, bro.

I got the flapper wheels, will report back.

[VinnyVincent]

Thanks for everyone's help, I am pleased with the results!



I ended up buying a buffer from harbor freight($40) as my bench grinder was only 5" and I wanted the bigger buffing wheels.
In the end, the polishing job cost me about $105 factoring in tools purchased and materials. About half the price of paying someone and no long wait. The best part is I have all the tools now, so if I ever need to polish anything else it won't cost nearly as much.

The budget for the entire job is going to be through the roof by the time I route out the old balsa, refill with thickened epoxy and reseal them, but I am learning a lot so it's all good.

[Cheechako]

Lookin good!