To dremel or not to dremel?

Mar 31, 2005 29 Replies

Hi,



Is there anybody around that has any opinions/experience on using a dremel for sanding of putty on plastic airplane models?



Have been working on some old Italeri BF-110 1/72 set and been getting somewhat crazy from hours of sanding and sanding in order to deal with the extremely bad fit of this old set.



My local tools-outlet sells a product from a german company called Proxonn (adjustable speed 5000-12000 RPM ). But hesitated somewhat since I was unsure what accesories should/could used on plastic, since most was designed for metal and wood. Don't wanna ruin the model, right!



Any comments and suggestions are most welcome.



Best, Mads


I have a rechargeable battery "mini-mite" (or something like that). Even it is overkill for most sanding.

I have seen a "reciprocating" sander by Mico-Mark or Model Expo that looks like it might be more controllable.

However, if I try and sneak another tool or kit in the house any time soon, the consequences might be dire.

Not good. The dremel is too fast and will melt the plastic. There is also the liklihood of the sanding drum skipping and gouging. If you have large areas to sand one easy way is to staple sandpaper onto a thick slat (like a triple thickness wood ruler) It is easy to grip and there is a decent stroke length to make sanding comfortable. Plus there is plenty of sandpaer surface so that you don't require replacing the sandpaper often.

Yes...NO. I personally feel a Dremel tool is far too unwieldy to be of much use for working anything but metal, and even then I have some reservations.

Sand by hand, use a file, or even better - a Flexi-file. And buy quality kits from now on...

Hi Mads, picked this up on a site ( It;s in German) on how to adapt an electric toothbrush as a sander. check it out on

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regards JimboD

snipped-for-privacy@osc.kiku.dk (Mads Ipsen) wrote in :

With 5000 rpm you might be okay. Mine runs at 15,000 rpm, which is way too fast for sanding plastic.

There are two accessories you could use: sanding drums and sanding disks. The sanding drums are rather coarse, and hard to use on larger surfaces (the motortool gets in the way). I haven't tried the sanding disks.

I have had luck removing excess filler by using a nylon (I think) wheel brush that came with my dremel-type motor tool. The nylon material removes the filler without harming surrounding detail. Just to be safe, keep the tool moving.

HTH

Ron

you are the man for turning me on to flexi files. i will never flatten another fuselage curve.

Generally, I don't much like power tools, but sometimes they have their uses. I have the Proxonn machine, and although the speed is adjustable, the range is between too fast and far too fast. When I need to use it, I hook it up to the power supply of my old model railroad, instead of to the power supply that came with it. The railroad supply can be varied between

0 and 16 volts DC with admirable precision, so I can go as slow or fast as I need to be. An adjustable power supply from the electronics folks should work just as well; anything really, as long as the output can start at 0.

I haven't used the sanding accessories myself, but I have had some success at sanding with the diamond drills I begged off my dentist. Run 'em relatively fast, and touch the work very, very lightly. Be aware that some filler cures hard but brittle, and chunks of it may be torn off on contact with a power tool. The plastic doesn't suffer from this, so at worst you'll have to reapply filler should this happen.

Rob

The really ARE the ticket...can't remember how I ever lived without one.

yeah, you really don't need electric tools. if it's too thick, shave, then sand. smooooth.

Pure overkill. Way too much "tool" for the job; and thus too easy to overdo it, and "Oops!" it. Perhaps you can find a new technique of puttying; that will eliminate so much sanding. Are you thinning the putty? Squadron Putty, Testor's Putty (Bondo), etc....all thin with Testor's liquid cement. I thin it down quite a bit, and brush it on in thin coats. It dries very quickly this way, with very little shrinkage. And it requires very little sanding, as there is not much putty to deal with, as opposed to what you get, when trowelling it on, straight from the tube. For filling large gaps, you can also try something like A&B (two part epoxy) putty. This can be contoured and smoothed with a water-moistened brush or finger; and also therefore result in very little putty to spend time sanding away.

You can use other brands of power tools - I happen to own a Foredom flex-shaft tabletop model with the foot treadle/switch. It can rotate very slowly (~100 rpm - maybe slower) with lots of torque. I've found it far superior to Dremels though I keep a Dremel in the drill stand. Be advised, Foredom's are not cheap but their seven collets run up to

1/4" so they can be used with a wide array of attachments.

They offer sanding drums and disks or you can use Dremel's versions in it as well. It's a lifetime investment, very well made and easy to maintain.

Frank Kranick

Good advice for 95% of modelling. Now if you're doing something insane such as 'building' a TKM resin kit a Dremel is your friend - and saviour. The resin inside the body is so thick that a motor tool is the only way to get it out in one lifetime.

Bill Banaszak, MFE

If you need even to consider using a power tool to remove putty, you're applying WAY too much putty. Try applying the putty more carefully with a small spatula and then smoothing the surface with your finger -- moistened slightly with water or mineral spirits, depending on the putty's chemical composition -- before it dries. In addition to the the effort saved, less sanding means less loss of surface detail.

Charles Metz

I use the Dremel mini-mite almost exclusively over my cordless dremel, but even it is too fast (~5000 RPM) for delicate sanding.

I also have the Wahl reciprocating sander (the one sold by Mico-Mark), and though it does give you a different degree of control (it's reciprocating motion allows you to spread the load over a wider area) it's still is too fast for finish sanding. Also, being reciprocating, its utility is mainly limited to flat and large-radius surfaces and to edges.

Both of these tools are time savers for roughing-in and removing large amounts of material quickly, but with plastic, you're ultimately going to have to end up doing the final sanding by hand.

Yeah - I like keeping a fingertip touch on my surfaces while sanding. I'll even sometimes work the Flexi-file against a surface by backing it up with a fingertip. That tool really is the end-all.

It was the Teknics resin set for the F-14A cockpit that made me go out and get a Dremel belt/disk sander...couldn't think of any other way to get the huge plugs off the bottom of those cockpit tubs. Still using it today...for the same purpose in what is ending up to be a never-ending series of Tomcat builds. Need to get a speed control for it, though.

A very easy method of removing large "plugs", is to scribe them away, using the backside of a dulled #11 blade. You can have a complete 120mm scale resin figure, for example, cleaned up in 20 minutes (and while sittin' on the sofa watching TV...lol).

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