Norton Rapid Strip Brush

[JetStream]

Just found a neat article in West System's "Epoxy Works" (Number 21, pg 14), about using a rotary wire brush to establish a secondary bonding surface on old fiberglass. On the Triton it's probably not an issue because you can grind to your heart's delight and still have a lot of laminate bonding surface. On my project, laminate is at a premium and I didn't want to destroy the top roving surface by grinding into it for tab attachment. In the article, they tested the brush application against laminate sanded flat with 80 grit and got a PATTI result of 936 psi with the brush versus 726 psi with the 80 grit Jamestown Distributors doesn't normally carry them but ordered them special for me. They said a package of 4 would be about 20 bucks. Since I don't have it yet, I'll have to post later on my experience with it.

[Tim]

I thought that sounded like a great idea too. I have found that it's tough to grind all the old paint, etc. out of the bumps and ridges in the weave of the woven roving, even with the coars paper I've been using, and I don't want to go too crazy with the grinding despite the overall thickness of the Triton's hull laminate. So I'd be very interested to hear about your experience with the wire brush, as it's something I might want to try as well when the time comes to apply new fiberglass.

Thanks, Bruce!

[JetStream]

Finally had a chance to test the Rapid Strip Brush. Turns out it costs about $18 each and I did get them from Jamestown Distributors. It is Norton Catalog Number 01123. I found out that they are actually made by Monti in Germany ( www.monti.de ), and are sold under several brand names. Apparently the brand name with the greatest number of variations, is Wolfcraft with the "Hurricane" line. They (Wolfcraft) are also in Germany and I did not find an importer.

One interesting caveat is that the wire brush is labled for 2500 minimum RPM and 4000 maximum. Most electric drills are 2000 RPM or less and most angle grinders are more than 4000 RPM. I happened to need a new 3/8" drill anyway, so I purchased a Milwaukee model 0233-20 variable speed with a nameplate of 0 to 2800 RPM. I since saw the article's author at the IBEX show and he indicated that his testing was done with a cordless at about 1500 RPM.

I tried the device both on laminate for secondary bonding and in my drill press for stripping paint from metal parts. I was quite impressed at the performance. An additional nicety is that when the bristles dull on one side, you can take it apart and turn it over to run the other direction. I'll have to wait about 30 years (ha ha) to see how well it bonded, because this is a live test inside my water tanks and I don't intend to be trying to separate the laminate in the near future.

[Dave, 397]

I'm wondering if any stiff wire brush would be as effective. One can buy some fretty aggressive knotted cup brushes that are RPM rated to run on the arbor of a grinder. It seems like we are just trying to get something like a 60 grit finish...am I thinking in the right ballpark?
Thanks,
Dave

[Tony]

I don't know if y'all have Home Depot or Lowes stores in ME, but out here I've seen norton brushes at Home Depot, and I think at Lowes, so that may be a less expensive route to go when you consider shipping. With our very thin hull, I'll be trying this in the near future as well.

[JetStream]

One thing to consider if you are thinking of using a standard wire brush attachment for your drill or grinder, is that the Norton wire gizmo has a different mode of action. Rather than a scraping, burnishing motion, it is actually more like a needle scaler that impacts the surface similar to a very controlled grit blast. The "needles" are held into the soft center piece in a flexible way that allows the bristles to impact the surface and bounce away. I don't think a wire brush (of the normal ilk) would achieve the same results. I have tried a few different wire brush attachments and did not see the same effect as the Norton gizmo.

[Dave, 397]

Thanks, Bruce!
I think I am finally getting the picure on it.
Of course, I am always looking for how to make do with what I've got...I do have (somewhere) a needle scaler. May give it a shot-at obviously reduced line pressure-and see what it does. Assuming I can get the thing to operate efficiently without digging holes in the boat, do you think this would be effective?
Dave

[JetStream]

Actually, I have been considering getting a needle scaler. I think they could do a very nice job in certain conditions and with limitations. They only cover a very small surface so the area of work would have to be limited. We used to use them to clean rust and slag from weld joints before painting and found them to be quite good at that. Like you mentioned, they would be capable of harming laminate (like sand blasting) if the pressure were too high.

[Rachel]

I just bought one of these, for sanding paint off of woven roving, and I'm looking at my options for tools to mount it on for use in close quarters.

One limitation is that the specified "no-load" maximum speed recommendation for the base tool you attach it to is 4,000 rpm. I have two drills (corded and cordless) that max out between 1200 and 1500 rpm, so I could use those, but I'm trying to get into a narrow area, and they're so huge due to the right-angle style of a regular drill body. So, I'm looking at options, but not really finding what I think I want. I figured someone might have a suggestion for something I haven't thought of. Here's what I've checked out so far:

1) Variable-speed 4-1/2" grinder. This could work, as the rpm range is around 2800 to 12000, but I already have a grinder (one speed), so I'm reluctant to spend $100 -$150 for something so similar. Also, the orientation of the arbor compared to your hand and the stripping wheel seems like it might be awkward.

2) Variable speed die-grinder. This looks like it could be a handy tool. The wheel would be oriented "perpendicular" to the handle, like a drill, and it's very compact. However they're expensive, and - more of a nix-factor - it looks like the lowest speed is about 7,000 rpm.

3) I looked at various drills, but didn't see one wherein the arbor just comes straight off the end, like the die grinder. I might have missed one since I'm on a slow connection which isn't great for surfing. I saw right-angled drills that have a more straight body than a regular drill, but of course the arbors on those come out at a 90-degree angle to the handle.

4) Is there some family of tools that spin at 2,000 - 4,000 rpm that I'm completely missing?

Rachel

Edited to add: I called or looked for the wheel at Lowe's, a Do-It Center, a well-stocked local hardware store (Ace), and West Marine, and didn't find it at any of them. I did find it at Home Depot for ~$19

[Zach]

Hey Rachel,

Grab a dimmer switch for a ceiling fan and an electrical outlet from the hardware store. Chop the male end off a piece of a dead extension cord, and wire it up in a blue plastic two gang wall box, with a switch+outlet face plate of your choice. Then plug the spinning tool of your choice in and turn the dial to the speed you want. Don't really horse around with the pressure (Not even sure you can do that with a wire brush...) as its lowering the voltage going to the tool, making the amps go up.

If it doesn't heat up, or let out the magic smoke... your good to go. (Grin)

Then take out your infrared tachometer... Or suit up in a few sweat shirts, face shield and welding gloves, turn it on and see if it explodes or not. (Really big grin.)

[Rachel]

Grab a dimmer switch ...

That sounds like a great idea!

...suit up in a few sweat shirts, face shield and welding gloves, turn it on and see if it explodes or not.

Um... tell me how it works, okay?

R.