Hot Rods I need tips for sanding louvers

I’ve got over 200 louvers in the hood and deck lid on my ‘32 Ford 5 window and I’m approaching the paint stage. I’d appreciate tips from those who’ve experienced the joy of sanding louvers - primarily materials and techniques. I already know about the blood and misery part.

 

Buy LOTS of Bandaids!
I have experience!

 

I've never done Louvers but perhaps wrapping the sandpaper around different diameter rod, pattern files, etc. and using that instead of your fingers might preserve your skin and precious blood...

Perhaps a dremel type tool with it numerous types of abrasives might assist as well...

In Aviation we used to use a disposable conical (Cone Shaped) sanding roll that you turned onto a threadlike arbor with a 1/4" shaft that came in many different sizes and grits that could again work and keep the flesh away...

 

I think I would check out the gloves they sell for preventing knife cuts. They are fabric (Kevlar maybe?) and under $15 on line or in kitchen/cutlery stores.

 

Why not start by using paint stripper to remove most of the paint and then just do a final sand for prep for primer/paint?

 

I hate to break the news to you but when you finish the 200 louvers on the top you need to flip the hood and truck lid over and do 200 more on the back side.

There is gonna be some sore, bloody fingers by the time you finish but 2 years from now you will be glad you put in the time. HRP

 

Never had the privilege of preparing louvers, but to stop all the red stuff leaking, I was wondering if the use of a small wire wheel in a drill could be used across the razor sharp face, to ''smooth'' it a bit??
I use my wire wheel on the edge of fresh cut panel steel / exhaust tubing I'm working with, and it blunts it down nicely..

 

Further to the above...



https://www.empireabrasives.com/cartridge-roll-mandrel-with-1-8-x-1-1-2-pilot-and-1-8-x-1-shank/##

Pattern files...





These aren't cheap but I have used Nicholson and they do deliver...

All this said deburring and sanding is an Art...if you chose a mechanical means as opposed to hand be very careful to carefully abrade as it's easy to 'F' things up and once it's gone you can't put it back...

Once the sharp edges are gone your fingers should be able to pass these spaces for final insp and spot sanding to finalize your awesome Hotrod/Custom addition...


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The best thing I have seen to use on louvers is your good old fingers. Nothing else I found worked as well on the louvers I did on my car. Good news is you won't be picking your nose anymore when your done as your fingers will be down to stubs!

 

I think I wrapped the sand paper around a sponge after skinning up my fingers on mine. No matter how you do it you earn it.

 

Fingers and patience. Be careful you don't rub grooves either side of the louver, gentle pressure. Didn't have them last time I sanded louvers, but those 3M sanding sponges might be useful.

 

careful not to make grooves is the only trick. I used different sponge/rubber sanding blocks. I think I also used a 400 grit sanding sponge. really didnt have any issues getting cut by any of them, just the misery of sanding around them all.

My biggest "error" was shooting expoxy primer over mine and my gun decided to puke so there was a random strip of extra thick poly to flatten out. Ill louver again, but I wont poly them!

 

First step is to de-burr the front edges, a small half round file works well.
I wrapped thin duct tape around my finger tips, and used adhesive backed sandpaper folded, which prevents the paper from sliding on itself.
The bad news is, after paint, you have to start the cut and buff process. I found that to be harder than the paint prep.

 

Never used it on louvers, but a cheap oscillating tool with red Scotchbrite seems to work well on other similar shapes.

I just use spray adhesive to stick the pad to a worn out cutting blade. Dull hte blade on a grinder first the wrap the pad around the edges, glue on both sides.

As well as being super handy to make weird cuts in just about anything, sand inside corners with normal sandpapers etc.

 

I use files on the raw steel louvers initially, then go to 150 grit paper. The more difficult task will be painting......and block sanding/finishing the surface....... have fun!!!!

 

Abrasive rubber sticks. various shapes and sizes, McMaster-Carr

 

I have punched innumerable louvers over the decades, and primed, sanded and painted even more, usually scoring top in national judging. Doing this as part of my job, it is expedient to get it done efficiently and try not to lose money or lose the customer's patience. So here's some of what works well for me. First, you have to be dexterous. As already mentioned, one small slip with a file, Dremel or small grinder can cause an issue that can take hours to fix. In the bare metal, look closely for burrs on the louver slots and especially where the ends of the louvers terminate. IF YOU'RE CAREFUL, you can use a Harbor Freight air filer (about $8.00 on sale) and it will save hours. Also, as already mentioned, the less priming and sanding you have to do, the fewer opportunities there are for irregularities caused by sanding technique. So if you can get the metal work near perfect, you could ideally shoot for two thin coats of primer with perfect flow-out, one coat of sealer, then enough somewhat over-reduced color or b/c for adequate hiding and durability, avoiding those little runs at the louver ends and avoiding orange peel. (A couple of chapters could be written on this skill, so these few sentences can't cover all the little tricks and finesse, but you will get there). Now, if you do have to prime and sand, you will need a miniature block to keep the flat surface around the the louvers flat. A regular small, cheap rubber sanding block cut down with a hack saw into strips 3/4" wide will work, if you dress the block flat with 80 grit on a plate of glass first. You must keep the block flat and keep it moving in random circles to keep from leaving what I call "saw marks". These are straight-line gouges in the primer that show up in the paint. Guide coat is indispensable here. Also be careful not to gouge the block/sand paper into the ends or backs of the louvers. Be prepared to spend whatever time it takes and to do any re-do you cause. This is an area where shooting for perfection at every stage will actually save time in the end.

 

Thanks for the responses. Some good advice. I’ve already prepped the louvers and have the panels in DP90. Getting them primed, sanded, painted and rubbed out is what has me on edge.

 

Take the time to deburr now, even if you have to reshoot the primer.

A sharp edge will slice you, and it won't hold paint well, more chance to cut thru when wetsanding your finished paint.

 

In my punching days, I would have sanded down everything first before starting to punch, nothing like trying to rush louvers and having the die slip on paint then go sideways or rip the edge

 

The thing with priming/painting louvers is that if you are doing it nice, you're not just priming sanding and painting. You'll be blocking in between priming. Just when you think you are finished, you get to do it again. Paint sticks wrapped in sandpaper has always worked for me. Good luck and watch those edges.

 

I have done a bunch of them in shiny black.



The best thing I found for sanding louvers are 3M sanding sponges. Different from regular 3M Scotchbrite pads and they come in three grits.

3M 51115069642 Sanding Sponges, Aluminum Oxide, 1 Sided Flexible, Super Fine, Bulk Packed (woodworkerexpress.com)

Also when it comes to wet sanding and buffing, my advise is not to sand the louvers at all. Sand and polish the rest of the trunk lid/hood and stay off the louvers by 3.8 of an inch or so. Louvers are largely curved and if you do a decent job painting, there should be very little orange peel that would need to be sanded or buffed.

Good luck, take lots of pics.

-Abone.

 

A silly question--About how many of those pads would it take to do that trunk deck? I am trying to get my nerve up to sand the louvers in a hood so I have no idea.

Thanks.

 

Can’t you just blast and primer ?

 

Hire a really good body shop production line painter to squirt it. Some of those guys can lay base/clear that never needs to be touched again. I'm not one of them guys for sure but I have punched and prepped a few thousand louvers until I sold my press a few years ago. Nothing to add on technique...the guys above are right on. The key is to find what works for you. I sanded and rubbed the last ones I punched and painted last year and my 77 year old fingers suffered for weeks. Not Riddler louvers is all I can say...

 

Very helpfull . I already have the sponge blocks from 3m. I'm getting ready to do mine after the finish weld process. All 144 of them.

 

Ha. Everyone else said all there is to be said..... Well...... except.....maybe it should of been sanded b4 da louvers were punched. Had to say it. Everyone else was thinkin it. Good luck.

 

The best tip I can give is find a louver guy that keeps his dies sharp.

 

Everything was sanded to bare metal and the louvers deburred before the DP90 was applied. I’m now getting ready for sanding primer and PPG single stage urethane.

 

...well almost everyone...

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