Sanding disks not lasting

Stuart 28-2

Member II
Using a 5" orbital disk sander for sanding the bottom as part of prep for bottom paint. The disks aren't lasting for peanuts. The sanding surface looks fine. It's the loops that fail. A new one fell off after just the amount of sanding in the photo. I emptied the little catcher that is attached to the dust outlet, then put the disk back on and it flies off immediately. I put on a new one and it's fine for a out 5 minutes.
Anyone know what I'm doing wrong?
Surely they should last better than this.
Second make of disks I've tried. Sander was new yesterday. Craftsman sander and now Craftsman disks.
 

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gabriel

Live free or die hard
Using a 5" orbital disk sander for sanding the bottom as part of prep for bottom paint. The disks aren't lasting for peanuts. The sanding surface looks fine. It's the loops that fail. A new one fell off after just the amount of sanding in the photo. I emptied the little catcher that is attached to the dust outlet, then put the disk back on and it flies off immediately. I put on a new one and it's fine for a out 5 minutes.
Anyone know what I'm doing wrong?
Surely they should last better than this.
Second make of disks I've tried. Sander was new yesterday. Craftsman sander and now Craftsman disks.
What grit are you using? I had this problem with the finer grits but went away with coarser ones. I’m using a corded dewalt sheet sander with paper clamps on it.
 

toddster

Curator of Broken Parts
Blogs Author
Never really had that problem - seems like either the pad on your sander needs replacing or you have a bad batch of discs.

However, it seemed to me that a drywall screen was the easiest way to remove old bottom paint. Except the last coating of ablative paint came right off with a pressure washer. Easy.

7759_media_1.jpg
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
As Toddster says, the pad on the orbital sander is replaceable. The hook and loop pad wears out after lots of use--but of course a new sander doesn't need replacement for what, 50 hours?

Unlike me, you have never accidentally bought sticky-back sandpaper, which certainly does fly off a hook and loop pad dramatically.
 

Dave G.

1984 E30+ Ludington, MI
I emptied the little catcher that is attached to the dust outlet
You should try using a vacuum attached to your sander. That on board little dust catcher will not be able to handle the volume of debris which will cause the hook and loop to fail. Debris is pushed in between the sand paper and the pad when it can't escape.
 

Stuart 28-2

Member II
I haven't done a bottom since finding this set up, but it's worked really well for other projects.


I got those sanding disks and they did not fly off. At same time started applying less force to sander.
 

Stuart 28-2

Member II
You should try using a vacuum attached to your sander. That on board little dust catcher will not be able to handle the volume of debris which will cause the hook and loop to fail. Debris is pushed in between the sand paper and the pad when it can't escape.
I have two Shop Vac's. The hose for one is too small, the other too large. However, I will pursue this further.
 

Stuart 28-2

Member II
The folks at Woodcraft in Charlotte, NC may have hit on it. They said I'm applying to much force on the sander. Will cause too much heat and melt the loops on the disks. I backed off and didn't have the problem again. However, at same time I went to better disks.
Will try the original disks again and see.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
FWIW I have a Fein "dustless" vac. The hose plugs into the dust port on a quarter sheet sander. Wonderful!
This vac version was semi-affordable because it does not have the automatic-on tool power feature. I am not sure they offer this cheaper version anymore. Anyhow it works SO well! Appearance is sort of like an orange "R2D2"..... !
:)
The actual hose fitting size must be a bit over an inch, probably metric. The present "Turbo 1" model might the replacement for it, albeit with more features.
 

Gaviate

Member II
I have two Shop Vac's. The hose for one is too small, the other too large. However, I will pursue this further.
I typically never run a sander without a vacuum attached. I consider the dust catchers that come with the unit to be whimsical at best. There are multiple adapters available for different hose sizes, but if I find myself without, i just use tape...sort of an unseemly arrangement but it does work. When I did the bottom on Emgee this past spring I started with 80 grit paper then quickly changed to 40 grit, then back to 80, then fairing work then last pass with 100 grit. 9 layers of paint to remove and shop vac collected over 30 lbs of "dust". Use moderate pressure and let the sander/disc do the work.
 

Dave G.

1984 E30+ Ludington, MI
I have two Shop Vac's. The hose for one is too small, the other too large
Yeah I had the same problem. I used painters tape wrapped around the nozzle until it was a tight fit & then a couple of wraps over the joint to hold it in place.
 

trickdhat

Member III
Blogs Author
I struggled way too long with the stock hose on my shop vac. It seemed to never fit the tool and wasn't very flexible. I finally ordered this set up a few years ago. the quick connect fittings and flexible hose make it really easy to use. With the mesh sanding pads and a vacuum on the Bosch, there's very little dust.

 

LemmyK

Member II
I use my Makita polisher with a 6" rubber pad and peel and 3M sticky back disks (blue). It's heavier for sure but the disks stay on and it cuts soooo nice if you slow down the RPMs.
 

Greg J

New Member
If I may be so bold as to suggest ditching the orbital all together. We tried it when we picked up our E39, but it was painfully slow. What we found that worked very well was a disc sander with a 40 grit disc, and a 2" paint scraper. They make short work of the paint but require care not to gouge the gelcoat. I used the scraper more than anything because they numerous coats of paint came off in sheets generally.
 

bigd14

Sustaining Member
Blogs Author
I struggled with the big box stores hook and loop sanders the same way, the loops are not durable, they melt, fill up with dust, switches fail, overheat etc. I went through a Ryobi and 2 Rigid sanders before I gave up on them. They are not designed for serious boat work!

Mirka makes a product called Abranet, which is a mesh sanding disk. I find it sticks very well to the hook and loop where other solid disks do not. I see they have a 40 grit called Abranet Ace HD. https://www.mirka.com/ABRANET-ACE-HD-AH0/

If you do not need dust collection look into the Porter Cable 7345 Sander and Mirka Coarse Cut or Gold sanding disks. These are adhesive disks but they do last really well. The tool is relatively inexpensive and bulletproof. I spent hundreds of hours behind this sander on my E27 project sanding everything from newly laid up rough fiberglass with 40 grit to primer with 220 grit. Great tool and great sanding disks. The pad on the sander will eventually get dust in it and shoot sanding discs across the boatyard (wear your safety glasses!), but you just clean it off with acetone and its ready for the next disk.

I have also used my DIY yards Bosch 6 inch ROS for bottom paint with dust collection and the hook and loop system seemed very robust.
 
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