DIY Back riveting plate - question

I decided to make my own back riveting plate for a couple of reasons that included saving on shipping and having it the size I wanted...

I got the plate yesterday.. It's hot rolled steel (could not find any cold rolled steel), 5/16 thick, brand new... It's never been outside. It's coated with a red oxide primer.

This is how it was when I got it :


Then, after 1 hour of sanding with a orbital sander, the result was that :


I only did the left side.
Got a couple of questions for people who did their own plate...
1-I started with 220 grid sand paper... The plate was already quite smooth but the primer was really hard to remove. Should I start with rougher paper?

2-I tested back riveting on it on a scrap piece... this is how things came up :



As you can see, the texture of the plate did show up on the rivet's head... The riveting tape helped a bit I think... but I'm not sure.

Is this satisfactory?? I was able to get to the shiny metal on one edge of the plate... but I doubt I'll be able to get to it on the whole surface... From the look of it, it seems the top of the plate is filled with small holes...

My brother works for a machine shop, he can probably use a face mill to make things better... do you think it could work?

Thanks

Just take it to a machine shop and ask them to "grain" it. Shouldn't cost too much, depending on how big your plate is.

Philippe,
What you really don't want is to scratch the skin.
Other than that ... nice size plate!

It looks really good to me!!

Stone it

Take a fine stone like one you use to sharpen you wife's knives. run a figure "8" over the surface. it is faster than you may think with a true flat surface

Hotrolled plate is going to have a layer of hard mill scale on it, you need to first get this off. You will need a much rougher grit paper, I would start with somethin in the 40-60 range. I dont think that it was the primer that was difficult to remove, but the fact that it was filling up all the voids in the relativly rough mill scale. Once your through the scale, you can work your way up in grits to get the finish you desire.

I picked up a piece of plate at the scrap yard. I used a hand held belt sander with a four inch wide belt to get the rust off my plate. Then I polished up the middle using my ScotchBrite wheel.

G-force said:

I dont think that it was the primer that was difficult to remove, but the fact that it was filling up all the voids in the relativly rough mill scale.

Click to expand...

You're right, if I look closely, the surface is full of pits...

Thanks all for the quick answers.

I used a belt sander to smooth mine out. It seemed to work fine.

The picture makes it look rougher than it really is.

I was able to make it smooth!

I borrowed my father's belt sander and started with 36grid sandpaper to remove all the mill scale


Then, I went up the grid... 50,80 then 120. After that, I switched to a 5in orbital sander. 150,220,320,400 then 600. Then polished it with mothers paste.




It looks good. The surface is really smooth. Took around 2 hours to do the whole thing. The size of the plate is 10in x 20in

That looks awesome. Well worth 2 hours.

Don't waste the time trying to polish it. Just take it to a machine shop with Blanchard grinder and have it grained for a few bucks. When I took mine in and explained to the guy what it was for, he was so interested in the concept of building a plane himself that he wouldn't even charge me! Probably cost him $80K instead!