Problems Stripping to Bare Metal

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PostPosted: Mon Mar 21, 2022 4:26 pm
niget2002 wrote: I've used 40 grit to strip paint off of metal before nice and quick. You're not going to sand the metal much. Just trying to get the paint pulled off most of the way. Then come back with 60/80 to finish up.


Okay, I'll try some 36 (or 40, if I can find it) grit first, since that's easy to do and costs almost nothing. But I suspect the mobile blaster might get a better result, so I'm still going to find out about that, just in case.

Thanks, all!



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PostPosted: Tue Mar 22, 2022 5:10 am
tell us what this da sander/ polisher is. make and model, please.

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PostPosted: Tue Mar 22, 2022 10:15 am
tomsteve wrote:tell us what this da sander/ polisher is. make and model, please.


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PostPosted: Tue Mar 22, 2022 11:18 am
Here's my Makita 9227C its variable speed and has plenty of power works great as a sander and a buffer. the air ones work good also, lighter and easier to handle BUT use a massive amount of air you'll need a minimum of 15CFM.
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PostPosted: Wed Mar 23, 2022 1:54 pm
badsix wrote:Here's my Makita 9227C its variable speed and has plenty of power [...]


According to the specs, the Makita is more powerful than mine (based on rated current draw of 10 Amps vs. 4.5 Amps) but I don't know if a more powerful motor would make any difference for me since I'm not applying enough pressure to cause mine to slow down... or should I be doing that?

The specs say mine is actually capable of a faster speed than the Makita, which I think should mean it can remove material quicker... but I don't know... maybe the Makita would strip better because it's not a DA (I think).

I still wonder if there is anything unusual about my paint that would explain why sanding doesn't seem to do much... that primer seems very hard <grin>... Even with 40 grit I can move the sander slowly over a small area (8" x 8") for 30 seconds and barely see any change... is that normal?

Thanks,



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PostPosted: Wed Mar 23, 2022 6:24 pm
96EbonyBird wrote:
you could use air tools, air sander


Okay, I didn't think an air sander would be significantly better than an electric, but I'll look into that some more...

you can use a 9227C Makita angle sander its variable speed good for sanding and buffing


Isn't that an electric model? If so, I'm already using something similar (a 6" variable speed DA sander/buffer model that spins up to 6500 RPM) so shouldn't mine work as well or better as that one? Again, I'm no expert on this stuff, so if I'm missing something please let me know.

with the 36 grit and the Makita sander you should be able to strip that car 2-3 hours


I did consider trying 36 grit paper on my DA but was worried that could damage the underlying sheet metal... am I being too cautious?

You can pay to have a mobile service to blast it at your home soda or hydro


Wow, Rsrguy3, I never thought of that, but a quick google search found multiple companies in my area (So Cal) that do it... I'll look into that!

Thanks all!


Try this guy, he'll come to you

https://youtu.be/CcAyOYkUC4g

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PostPosted: Wed Mar 23, 2022 7:06 pm
96EbonyBird wrote:
badsix wrote:Here's my Makita 9227C its variable speed and has plenty of power [...]


According to the specs, the Makita is more powerful than mine (based on rated current draw of 10 Amps vs. 4.5 Amps) but I don't know if a more powerful motor would make any difference for me since I'm not applying enough pressure to cause mine to slow down... or should I be doing that?

The specs say mine is actually capable of a faster speed than the Makita, which I think should mean it can remove material quicker... but I don't know... maybe the Makita would strip better because it's not a DA (I think).


The difference is that the Makita is rotary, so it spins around like a wheel does on an axle. Yours is a DA, so (depending on model), while the base will spin, it isn't driven to do so and the whole base moves in orbits of 3mm or 6mm or bigger, kind of like your hand when you're polishing. Movement for a rotary is given in rpm (revolutions per minute) while a DA is opm (orbits per minute). A rotary speed of 2000rpm is roughly equal to a DA speed of 6000opm. The rotary however, is much more aggressive and can achieve much faster results. It can also do damage more quickly.



I still wonder if there is anything unusual about my paint that would explain why sanding doesn't seem to do much... that primer seems very hard <grin>... Even with 40 grit I can move the sander slowly over a small area (8" x 8") for 30 seconds and barely see any change... is that normal?

Thanks,


The top layers are usually quite hard and take a bit more work/time to break through. Once through, though, coarse grit on a DA will work quite quickly.

For stripping larger areas I like the paint stripping disks (like the black one in badsix's photo). Extreme care though because it's for use on a rotary and too much pressure can dent the metal or going too slow with too high rpm can heat and warp it.
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PostPosted: Thu Mar 24, 2022 3:04 pm
Rsrguy3 wrote: Try this guy, he'll come to you
https://youtu.be/CcAyOYkUC4g


Cool, thanks! I left a message for him, just waiting to hear back now.

NFT5 wrote: The difference is that the Makita is rotary [...] A rotary speed of 2000rpm is roughly equal to a DA speed of 6000opm. The rotary however, is much more aggressive and can achieve much faster results. It can also do damage more quickly.


Ahh, okay, good to know. I do have a variable speed (up to 2500 RPM) power drill with a 5" sanding pad, so I think I'll try a test area with that to see if I get faster results.

NFT5 wrote: For stripping larger areas I like the paint stripping disks (like the black one in badsix's photo). Extreme care though because it's for use on a rotary and too much pressure can dent the metal or going too slow with too high rpm can heat and warp it.


okay, thanks!



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PostPosted: Thu Apr 07, 2022 9:16 am
With that much to strip and no compressed air have you considered a stripping tool? It's made to do exactly what you are doing and is WAY faster than anything suggested so far except blasting or dipping the entire body.

Harbor Freight has one that's identical to the Eastwood one but cheaper at about $150 so not real cheap but you have a LOT of square feet to do and time will become a factor!
I think you are using too fine of grit and you need something with more bite.

Looks like this;
Paint Stripper.JPG


https://www.harborfreight.com/9-amp-surface-conditioning-tool-58079.html
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PostPosted: Thu Apr 07, 2022 11:32 am
clubairth wrote: With that much to strip and no compressed air have you considered a stripping tool?


I hadn't considered that, only because I didn't want to buy a power tool that I would only use once... but I suppose doing that would be cheaper than paying someone for sandblasting.

I did try my power drill with a 5" backing pad and a 40 Grit disc and that did remove the paint faster, but it was also very hard to avoid random scratching of the metal... I guess I just need to practice more.

Thanks!
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