Which sander for refinishing a vintage travel trailer?

[Rob]

My wife and I bought a 50's Jewel travel trailer and want to refinish it and convert it into a concession stand.  The metal skin on the outside has a pattern of shallow ridges every few inches, as you can see on this similar-looking trailer:

We've gutted the inside and she's started sanding the outside.  At first she was using my Bosch 5" oscillating sander, but she kept pressing on the corners which stopped the sanding pad from rotating and melted the velcro loops.  The sander just wasn't aggressive enough, even with 40 grit paper.  Then she switched to my oscillating multi-tool's sanding pad, but that hook-and-loop pad burned up really fast.  Since we're keeping the trailer at a friend's house in another town, we don't get over there very often, so I want to be able to make a lot of progress each time we go over there.  I just bought an ETS 150/3 for woodworking, but I assume that isn't the right sander for removing the old paint.  I was thinking about either a Rotex for its aggressive mode or a linear stroke sander to get into all the ridges and grooves, but I'm really not sure which one would be best and I can't justify buying both at this point, even at reconditioned prices.  Which sander would you recommend, and which backing pad(s) and paper will work best for this job?  Also, are the Festool pads more heat-resistant, or are we going to burn through those, too?

 

[tbellemare]

Whatever you end up using, you need to use dust extraction, both for the lack of mess and because the air flowing through the pad cools it.

Tom

 

[bigjonh]

I had a lot of success stripping paint from metal with a rotex equipped with the interface pad.

 

[AlexThePalex]

I would do that with a Rotex, either the RO 90 or the RO 125. Certainly not a linear sander like the LS130, that would take ages.

I'd also work on the trouble spots only, the places where the paint is still good only need a light hand sanding before you paint. From what I can see on your pictures, the trailer's paint looks in a pretty decent shape.

And for the burning of the pad's velcro, no reason that should happen except for really pressing too hard. I always put a lot of pressure on my sanders when I'm removing paint, but I never burn anything.

 

[Rob]

Thanks for the feedback, guys.  A little more info: the trailer has been repainted before.  I'm not sure if it's necessary but we're trying to get down to the bare metal.  Who knows, maybe we'll like the look of it and instead of repainting it we may decide to just polish it up and optionally put on some clear coat.

I think when my wife was sanding, she was tilting the sander and just using the corner of the sanding pad to get into the grooves in the metal.  I know it doesn't take much to melt the velcro on my oscillating tool's sanding pad, but I was disappointed that the ROS pad's velcro was also worn around the edges.  Will the interface pad let the RO 125 get into the ripples and grooves on in the metal?

Does it make any sense to consider a DX sander, or would that be just as slow as the linear sander?

Also, what's the difference between the RO 125 EQ, RO 125 FEQ, and RO 125 TL?  I've seen all three designations used but couldn't find a direct comparison after a few minutes of searching.  My best guess is that the EQ is the predecessor to the FEQ, and the TL is just the FEQ but with a T-LOC instead of Classic systainer.

Thanks!

 

[bigjonh]

The interface pad is a soft foam pad that goes between the paper and the backing pad. It allows for irregular shapes, I recently stripped down an antique iron bed down to bare metal with the interface pad and my RO90.  It took awhile though.

 

[wow]

I hope this isn't sacrilege, but I wouldn't use a sander at all. I'd use what the auto-body guys would use, which is the 3M Roloc abrasives. You can use them with a cheap air die grinder like I do, or Milwaukee has recently come out with an M12 sander/polisher specifically for this purpose:

http://www.milwaukeetool.com/power-tools/cordless/2438-22x

You need high speed for the Roloc products to work best - Ideally around 10,000 RPM or so.

BTW, the Roloc discs come in 2" and 3" sizes, so they are perfect to get into those creases and clean 'em out.

 

[Rob]

Thanks for the extra info, guys.  I'll look into the Roloc abrasives and a grinder but I'm not sure if my compressor has enough CFM for a die grinder...I'll have to check.

My wife used a DA sander in her auto body class several years ago, so I bought one of those but it turns out I can only run it for a few seconds before I have to wait for the compressor to catch up.  I tried searching for electric DA sanders and found that that the closest thing is either an electric polisher or a dual-mode sander like the Rotex line.  Since the trailer is old and I don't know what kind of paint was used on it originally or when it was poorly repainted, I figured it would be a good idea to put as little of the paint in the air as possible.