The roof structure of our house is held up by a series of large wooden beams, with a very large 20 X 12" beam going down the center of the house and smaller beams hanging off it and sticking out the outside walls of the house perhaps 2' to 10'. Every now and them (3 years or so) we need to patch sand down the wood, apply insecticide and re-varnish. We have 100+ of these beams (the part exposed to the weather).

I have a dewalt orbital sander. We got about 1/3 of the way through the job and the velcro pads would not stick anymore. I ordered a couple replacement backing pads (from dewalt Mexico - a good 2 day drive away). The new backing pad lasted perhaps one day and again the sandpaper is not sticking.

Am I over-using the dewalt sander ? The motor is working fine. But at nearly $.7 USD for each piece of sandpaper and $10 USD for each backing pad this could make an expensive project even more expensive.

Thanks

 

I've never used a sander with the velcro pads so I can't help there but I question the use of varnish [or spar urethane] on the exterior of a house. That isn't a coating that wears well when exposed to the elements. Varnish on the interior portion should last decades. I'd suggest going to a local paint store and discussing the coating options to hopefully find one you'd be happy with.

 

Thanks for your input. This is the description from the manufacturer's web-site

"Transparent wood varnish gloss finish, good toughness, high strength and durability. It is ideal for floors and wooden surfaces household, indoors and outdoors. Recommended for its easy application in temperatures between 10 ° and 40 ° C. Areas recommended use: Siding, particleboard and solid wood that are indoors and outdoors."

Google translate does a good job with it.
River Barniz 610 Spar Marino

There are a lot of houses around with our type of construction - and they sell a lot of this product.

I mix it 1 part thinner and 5 parts varnish.

Thanks again.

 

A couple things... the hooks do eventually wear out, so that's not surprising. What is unusual is how fast it happened. The heat from the friction is basically melting the hooks and flattening them out. The mistake most people make with orbital sanders is pushing on them while they sand... that creates too much friction and heat. You find a spot you want to really sand well and so you push the sander into it... which is really hard on the sander disk. All you need to do is hold the sander and move it around, let it do the work. So I guarantee you are probably pushing too hard on the sander. Also sanding varnish gums up the sandpaper. What grit are you using? And are you trying to remove all the varnish or just scuff it up? If the paper is getting gummed up, replace it. And don't booger up the edges of the pad by sanding too close to the edges of things... that just tears up the edges of the paper and pad, speeding its demise.

If your sander speeds up and spins out of control when you lift it off the surface, you also need to replace the brake (cfs disk).... the white/ivory rubber ring directly under the sanding pad.

 

I agree with Brant. I worked on a house where a paint contractor had his helpers sanding log siding to prep for a finish. He had 4 ROS units laying on the porch. I asked why so many and he said they were sorry and didn't do the job. I observed his helpers (teens) pressing with all their might to get the job done. The ROS's were Milwaukee and were not by any means "sorry". I informed him of the problem and he reluctantly told his guys how to use them properly.

I buy the velcro replacement disks in two packs because the hook sheet doesn't really adhere to the disk unit very well. After 6 months or so, it starts separating. Just the nature of the beast.

 

Now here is a man who knows his orbital sanders ! You are probably right - we may be pushing too hard. I wish I had bought a few more of these backing disks when I bought the last couple - they take 2-3 days to get here. Home depot (here) would love to sell you a new sander - but they carry no replacement parts...

I saw a you-tube video where the guy was gluing the paper to the backing disk to get a little extra life out of it. I might give that a try as well - while I wait for some more backing disks.


Slightly different question - I am looking at two of the pads; a perfectly new one and one which was used for a day. The used one has a 1/4" shiny circle between the holes and the outer edge - is THAT normal ? It is like something is wearing on the metal part of the pad.

Thanks.

 

six months - we are talking 1 day :-( And you are right - I have some help on this project - or it would take me months by myself. As it is we have been at it for 2 1/2 weeks.

 

I could swear that last time I was in Lowe's they carried the replacement pads in stock. Course, every store probably stocks different items.

There really isn't any part of the hook and loop pad that is metal, aside from the top plate that faces the sander. And yes, when the loops outside the holes start to get flat, it's on it's way out. Under normal use (sanding bare wood) when you treat it right by not pushing on it, it may last a year or more, depending on how much it's used. But like I said, it's the abuse from pushing on it and the gumming of the sandpaper that is leading to its early demise. I would surmise that you are getting a ring of superheated melted varnish on your sand paper in the exact spot that the hooks appear melted/flattened. And if not, that's still where the most friction is... on the outer edges. You can't sit in one spot long or it heats up. A good technique is to wave the sander slowly back and forth, left and right... not pushing... just waving it. It may also help if you take your hand off the TOP of the sander and hold it along the side of the body... like holding a glass of water. When you hold the sander like that it's almost impossible to push too hard. And try not to tip it to get close to the edges...

 

Marksr - I think I know the answer to this but I'll ask it anyway. We have these wood beams that support the house and on top of them are these 1" X 12" X 18" clay tiles (I'll be they make houses like ours in CA). On top of those tiles are several other layers including bricks and more tiles - when all is said and done the 'roof' is between 7" and 9" - the top of the barrel tiles.

Well the bottom of the lowest layer of tiles was showing signs of saltpeter. So it was suggested that I apply red waterproof paint. Well I tried that in a small section - unfortunately in a much to obvious small section - and it was not the right thing to have done. In hind sight - those tiles were NEVER painted. They are just terracotta tiles (like a plant pot) which have been sealed.

I can't replace the tiles I've painted. I've tried painting over them trying to get a better match with the other tiles - just not quite getting there.

Any thoughts ?

 

This is the part I buy. Just so we are on the same boat. Sander Pad (Hook and Loop) [51-36-7100] for Milwaukee Power Tool | eReplacement Parts

On an older pad that may have had inordinate pressure applied, you will get that ring on the outside. Not applying too much pressure will not result in that.

 

Unfortunately - the nearest Lowe's is about 1500 kms away.

 

Chandler - yes, this is the part I am using :

http://www.amazon.com/DeWalt-Sander-.../dp/B00CA6MOHE

Except I bought them from Dewalt Mexico in Monterry Mexico - shipping next day (Friday<->Monday) was about $8 USD ( a lot less than the gas to go there myself).

 

Thank you all - you have been very helpful.

 

I have a Porter Cable sander and never had a problem with the hook and loop failing. I went through quite a few sanders before sticking with this one.

 

That's funny Brian, what model do you have? The Porter Cable 382 and the Dewalt DW721 are practically identical. And their hook and loop pads are interchangeable... right down to the same part #... 151281-08

I've actually been thinking about getting a new sander one of these days.

 

One thought in passing. When applying your disk, be sure to line up the holes on the disk with the holes on the drive disk, or your suction won't work.

 

I think I've had my sander for more than 10 years, Porter Cable #333, 5".

Maybe it's the sanding discs, I use Norton and they hold really tight, almost too good.

 

You really only have two options, remove the paint and go back to a somewhat natural finish or try and get paint that will match. Just painting select tiles will probably never result in a perfect match as the tiles themselves don't have a consistent solid color. The only experience I've had painting those types of roof tiles was on a house where they used different brands, lots and discontinued tiles to save money and then weren't happy with the look. We used a special solvent based paint but I never saw the house again and have no idea how well it held up long term [that was about 30 yrs ago]