The David Union DU400 Pencil-Style Hobby Sander

by John Miller

Since starting Model Paint Solutions I’ve had the opportunity to build way more models than I did pre MPS. I’m not complaining mind you but the hand strain I began experiencing after spending more time at the bench wasn’t all that fun. Like many modelers I tend to hold the model part with a 5-ton G.I Joe, Kung-Fu grip and use a similarly tight grasp on the piece of folded sandpaper or file I’m working with. The result, of course, is hand strain. As many of you know scale modeling is a tough sport and injuries are common

I was beginning to contemplate the purchase of an electric hand sander or similar tool when I received an email from Jerry B. up in Denver telling me about this nifty new pencil-style sander by a company called David Union. One thing led to another and soon enough I had one of these beasties in my hands and for the last 2 months its been subjected to the rigorous MPS Workbench Test. This little hummer passed with flying colors; what a neat tool! This sander not only saves your hand from muscle strain and cramps, it saves you time as well, a lot of time.

The DU400 is manufactured in Taiwan by the David Union Company and distributed within the US by T-Rexx Tools (email: trexxtools@gmail.com). The design incorporates a short-stroke (3mm) electric motor capable of producing 1,000 to 6,0000 rpm. An on/off-variable speed dial on the rear of the body allows the required speed to be easily set. The cord plugs into the rear of the unit and is out of the way while the tool is in use.

On the working end of the sander a screw-collar holds one of seven sanding styluses (and 2 metal abrasive bits). The styluses, made of a hard black plastic, are very resilient but with a bit of give. Most of the styluses are small, comparable to the size of a #11 X-Acto blade. Each stylus has an angled head and this, combined with their small size, makes maneuvering them into restricted spaces easy. This is an important consideration if ones preferred scale ranges from large 1/144th and larger.

The DU400 comes with three packs of adhesive-backed sandpaper of 240, 400, and 600 Grit. Each pack has 10 sheets of paper that’s 41/2 by 2¾in. A set of cutting templates (same sizes and shapes as the stylus heads) is provided to make cutting matching pieces of sandpaper easy.

• 
• 
• 
• 
• 

• 
• 
• 
• 
• 

• 

Thumbnail panels:

Removal of a used piece of paper from a stylus is easy since the hard black plastic is resistant to Lacquer Thinner or even straight hardware store Acetone. That being the case, many spray adhesives can be used to affix whatever grit sand paper is desired onto any of the 7 styluses with the knowledge that it can be taken off with Lacquer Thinner if need be: very handy. 

I decided to give my DU400 a test drive by using it on my Tamiya 1/48 F4D Skyray that’s being built with the leading edge slats in the retracted position. The slats are supposed to be glued in the extended position so the parts don’t fit retracted willingly or with the quite the right shape. The easiest remedy was to fill the offending areas with my favorite filler, CA glue and talcum powder, then blend the slat and re-scribe where required.

In the accompanying photograph, the right portion of the slat still has CA/Talc putty versus the left side that was blended with the DU400 fitted with a stylus that had been covered with a piece of the 400 grit adhesive-backed sandpaper supplied with the sander.

Using the right combination of speed (controlled by the rpm dial on the sander), pressure, and angle I was able to not only remove the putty from the model but also blend the surfaces smooth. This was accomplished in 2-3 minutes using just the DU400.

The importance here is finesse. To be capable of removing putty and quickly re-contouring styrene is handy. To have the finesse to blend surfaces of putty and styrene so as to be smooth and ready for primer is ideal.

In addition to the sanding styluses the kit comes with two metal abrasive bits with black collar adapters. I’ve found these bits are great for an initial clean up of parts while they’re still on the sprues thereby saving my hand the strain: awesome.

What a nice tool! From the heavy-duty storage box to the angled styluses to the pencil-sander itself: the whole package drips of quality. I ran my sander at a high rpm with a load on it for many minutes at a time and couldn’t make the unit over heat or act up in any way. The styluses are small with angles that make getting into tight areas possible. The thirty sheets of sandpaper (10 each of 240, 400, and 600 grit) that are provided will last a long time. However, the lacquer thinner-resistant styluses permit many spray adhesives to be used to affix whatever grit sand paper is desired. This is a quality tool that will save both your hands and time.

The DU400 Sander, replacement sand paper packs, and styluses are now available from ModelPaintSolutions.com.

Thanks for reading along!

Text and Images Copyright © 2020 by Model Paint Solutions
Page Created 26 June, 2020
Last updated 26 June, 2020

Back to HyperScale Main Page

Back to Reviews Page