Thread: Which sander for the job?

Originally Posted by justinmcf

a small sander would be a waste of time for sanding a whole house.
.

It would be like washing your car with a toothbrush

I'm surprised that others are recommending the big Rotex.
When I've been sanding my own weatherboard on the shack & various houses that I've owned over the years, i've much preferred a grinder and 24/36g discs.

I've actually tried the Rotex: and been pulled off a ladder when the disc jams between weatherboards.

It's probably better to be guided by what the professionals use with leaded paints: a variable speed grinder and the best particulate mask money can buy.

Remember that the lead in paint is at very small concentrations, and that in reality it's probably counterproductive to attempt to remove all the paint anyway. Just the loose, flaky, cracked sections, and to provide a "key" for the next coat.

I own and use a Metabo LF 724 paint stripper, and find it useful for the intersection between weatherboards, where other tools fail miserably. But this area usually has the most intact paint finish, being protected from sun and moisture, and least need of stripping. I don't really use it on weatherboards any more.

I also have an RO90, which is a delight to use. While I haven't actually used it on weatherboards, I have used a slightly smaller equivalent (Metabo SXE 400) with a 2.5mm orbit & 80mm. dia. pad. Great sander, only average papers (Hermes & Klingspor I think) stearate coated 40g. These sanders are superb at the delicate task of cleaning but preserving the bullnosed moulding on the weatherboards, a task impossible with a larger sander. I actually have 4 of these Sexy 400s now, but think the RO90 the better sander, albeit a bit bulky in comparison.

For removing the majority of the flake, however, and the primary tool for the job would have to be the v/speed grinder. It's just so fast, gentle, and "right" for the task. Ask any painter. I use a very old B&D/Elu 115mm. and a 125mm. Metabo. I also have a couple of 1400w Bosch, but they're much too much grinder for the job. Think small, think one hand, a lock-on switch and a speed of about 3-4000 rpm and you're getting there. A nice soft and flexible backing pad and some quality Norton or Carborundum papers will see the task done quicker, neater and more effectively than any other way. There really won't be a great lot of dust to clean up anyway, as the coatings are mere fractions of a millimeter thick, and dont need to be entirely removed anyway.

I'm really astonished that seemingly all the advice offered so far has been almost the exact opposite of mine, as I've tried the other methods, but found the grinders and smallest ROS to be the safest, neatest and most efficient.

As an aside, after having painted/renovated 8 houses over 40 years, most with leaded paint I was concerned about absorbtion of lead, and about 10 years ago had the whole family tested for residual lead concentrations.
The result? Utterly undetectable!

Hi guys,

this ratbag dude is no dickhead, I have skimmed over this thread and rejoiced to find someone with up there for thinking. Stripping a house is not a piece of art, it is a job to get done pronto! 9" angle grinder, most coarse grit you can get or those hairy ones! Blades the paint off in seconds, use the grinder lightly and quickly! Change grit often!
Don't want heat to melt the paint! Clogging you know! When you've done all the house with this get a scraper (go to the gym and work out a bit first) clean up the corners hey! Now you can use your rotex or whatever! Job done! Happy new year!!

Regards,

Oddjob1

my advice is based on dust extraction being a top priority.
i wont argue with people who think it is not important.
its their lungs, not mine.

the metabo paint stripper looks like a great tool and if i was doing a lot of renovation work i would seriously consider buying this tool.

however the original poster may end up with a tool that gets used once and then disgarded.

i have recentlty bought a second hand festool ras 180 from ebay.
i have not had a chance to run it through its paces.
but i know it would be a good option for this type of work.

the original poster mentioned the festool ras 115.
this would certainly be more aggressive than the rotex but again it is a tool that may not get much use once said job is finished.

i still recommend the rotex 150, as you can buy the same grit numbers as the ras 115.
and of course, dust extraction of the toxic lead paint will be at a maximum.
and at the end of the job you will still have a fantastic all round sander.

justin.

If you don't want to make this job into your lifes work, do as suggested but wear a mask and vac up after you, crickey!

Oddjob1

It all depends on your priorities. Personally, paint flakes and dust (and we are probably talking about a couple of hundred square meters sanded off here) are not something I want thrown all around MY HOME; in the garden, through doors/windows, in the air-conditioning, in the water tank, over my family, etc. And not over me either.

So whatever the actual sander or grinder used, I would not want to do that sort of job without dust extraction. I don't care how much faster it could be or how must less mucking around without extraction, but without extraction sounds like a horror-show.

But back to selecting the right tool - I would personally use a ROTEX 150, and let me elaborate why:

• With an extractor, excellent (really excellent) capturing of the dust at the source.
• With extraction the pads are kept relatively cool, so no worry about melting the paint, just removal of it.
• The edge protector is excellent for avoiding sanding/hitting/marking adjacent boards, etc. Which means it's much safer for an aggressive rotary action tool. Safety - Again the edge protector is going to help avoid sander fling and when up a ladder, that is important.
• Safety - if you drop a ROTEX (in rotary-eccentric mode) on you it is likely to do minimal damage compared to a tru-rotary tool spinning at thousands of revs more).
• Quality of finish, flat and un-gouged, no repair work required caused by the sander. Go as course or as fine as you require. Polish timber features if you so require.
• The Festool interface pads mean you can also tackle convex and concave curved surfaces with a lot of success, maintaining much more contact area than a flat pad alone can achieve. Perfect for bull-nose boards and other trim.

I am sure I can think of many more advantages if pressed.

And as mentioned, you have a fantastic sander for all other sorts of jobs once the exterior is done. Sand the interior plasterboard joints inside if you like, build a dining room table, polish your car, polish a marble mantelpiece, etc. And all with virtually no dust in your face or in the environment when used with a good extractor and the right abrasives.

Thanks for all the replies so far. Very helpfull.

Variable speed grinder and 36 grit has long been ruled out. Might well be quickest, but, dust control plays a big part in the decision I make. I also dislike the finish that these sort of machines produce. Quite often they leave gouges that are obvious after applying the finish coat, looks crap I reckon.

I am in the process of arranging a head to head comparison of the sanders in question. This will happen within the next 2 weeks, weather dependent. I will report back the findings.

I have a Metabo 150mm ROS and have tried it in a limited fashion, I'm reckoning it is just too big for the job. Remember that the house is clad with chamferboards about 90mm wide, the little fellas, not big wide weatherboards. Hence my interest in the smaller machines. I also have a small DeWalt machine with a small orbit, great for detail work, but unsuitable for the task I have at hand.

I am not overly concerned about using the machine for one job. I may keep it if I have a further future use, or I may sell it. Either way it will still be far more economic to do the job myself.

Speed is also a consideration as I will be having scaffolding installed around the house to replace the roof. Super Six removal by contractor, replacement in corro be myself. I am planning to strip and paint down to the window line while the scaffold is up, quicker and easier than tressels and planks.

The project plan is for scaffold hire for 3 weeks. Also, I will be spraying the house.

Cheers

Is the main flat surface on the chamferboards 90mm or the board is 90mm the the flat face is smaller again?

Anthony

80mm cover. Flat vertical face about 45mm, smaller face 30 deg off vertical about 35mm.

Cheers
Bevan

Originally Posted by Enfield Guy

80mm cover. Flat vertical face about 45mm, smaller face 30 deg off vertical about 35mm.

Thanks - so with a 150 or 125mm sander you could sand a number of boards at once (45mm vertical faces) - would that be right?

Have you looked at the Festool DUPLEX sander? Its a lineal motion sander and you can made custom block profiles to sand the angled sections and underneath the top board simultaneously.

Yes Anthony, that would be right. I can sand a couple of vertical surfaces at once with boards of this size. However the angled face presents different challenges. I am finding that, at least with my 150mm Metabo, the efficiency in dust control and operation drops markedly. But then I have little to compare with.

No, I have not considered the other sander you mention. I shall. Maybe I will get the opportunity to include it into the mix of options when I do the comparisons. Hopefully by the end of this coming week.

Cheers

Originally Posted by Enfield Guy

I have not considered the other sander you mention. I shall. Maybe I will get the opportunity to include it into the mix of options when I do the comparisons.Cheers

The Festool DUPLEX is quite a specialised sander, so unlike the ROTEX it will not find itself being used that much after the initial job you do with it, but when a similar profiled job presents itself, its once again a real winner. I originally bought one to do the front of my house, and it paid for itself (in time and labour) on that one job. Since then it comes out about once a year
for something tricky. So in the end I was glad I bought it when I did.

Well, what with the floods and having to go out and work to pay the bills, this project has, up till now, been put on hold.

I have made the appointment with the rep and will report back after the comparison has been made.

Cheers

Well, I have had the rep here and I compared the rotex 150 and the rotex 90. The results may surprise a few.

Remembering that the boards I need to sand are not weatherboards but chamferboards and therefor the surfaces are much smaller. The 150 was not that effective in sanding 2 boards at a time. The reason, I believe, is that the board pairs are not necessarily in the same vertical plane. This meant that there was rework to be done on the adjacent board. Also I found that the machine was difficult to control on the chamfer which is only about 35 - 40mm.

Dust extraction was also compromised due to the large area of the pad NOT in contact with the surface.

The RO90 is a whole other kettle of fish. I found that it is easier to control on the chamfer, Dust control seemed to be more effective, particularly on the chamfer and on the vertical surfaces it seemed to work better due to the pad being able to remain in full contact with the board being worked.

Other advantages are, the Delta head that comes with the machine and much quieter running. I was quite surprised by the noise generated by the RO150. A direct comparison between my Metabo 150 machine and the RO150 produced no significant improvement for this application. The Metabo is a much quieter machine in operation.

Therefor, I would recommend, for the application I plan to put the machine to, the RO90.

The added bonus is that I will have a smaller sander with a delta head to complement my other sanding options.

Cheers
Bevan