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Nose Strips for People Sewing Masks

The pandemic arrived in March 202 and I wanted to do something to help. I saw lots of folks were sewing masks locally for hospitals and first responders and they were being made either without nose strips to help shape and seal the mask where it fits over a persons nose or adapting household items that might not be stiff enough to keep the shape like twist ties or pipe cleaners.

I decided I could help and started making and giving away stripslike these:

Nose Strips

They are modeled on the strip I saw on an N95 mask. It was made out of a soft easily bendable aluminum allow. About 3.5” long and 3/16” wide.

N95 Mask Nose Strip

I meadsured it at about 0.045” thick.

N95 Mask Nose Strip Thickness

The corners on the ends were chamfered and smoothed a bit.

N95 Mask Nose Strip: Chamfered End

I first tried making the same size with some 6061 alloy aluminum I had but that was way too stiff and hard to bend.

I did have a sheet of 26 gauge galvanized steel sheet that I have used to patch rust holes in my cars so they would pass inspection and even though this metal ismuch thinner tna the aluminum (about 0.,017” thick) it seems to be roughly equivalent in stiffness to the aluminum strip used on the N95 mask.

I decided to:

  1. Use the same basic dimensions: 3.5” long and 3/16” wide.
  2. Round over the four corners.
  3. Smooth over all the sharp/rough edges created when making the strips.

They look like this now:

Nose Strips Rounded and Deburred

A mask fits and seals much better with a shaped nose strip.

Mask with Nose Strip

A closeup of the mask shape maintained by the nose strip.

Mask with Nose Strip: Closeup

The mask shape is maintained by the nose strip when it isn’t being worn.

Removed Mask Shape with Nose Strip

Here’s what 1000 look like!

1000 Nose Strips Rounded and Deburred

Making Strips

1. Cut the large sheet of galvanized sheet steel into 3.5 inch wide strips.

Using a larger shear at a friends workshop.

Using the 60 inch foot-operated shear

Later The Steel Shed in Bernardston MA used their big shear to cut 26 gauge galvanized steel into 3.5” wide strips.

2. Cut 3.5” wide strips into lots of 3/16” wide strips.

I used a small notching shear with a wood stop block glued to the underside of the moving shear surface to quickly cut the 3.5” wide strip into lots of 3/16” wide strips 3.5” long.

Small Notching Shear

Time lapse video of shearing 1800 strips.

3. Round over all four corners.

After shearing the strips they all have a slight curve.

I line up strips in blocks of about 25 and use a belt sander to round all four corners. This part of the process takes the longest.

Rounding all four corners on a stationary belt sander.

4. Deburr and smooth all rough/sharp edges

Putting strips into a vibratory tumbler filled with a ceramic deburring media and running it for 4-8 hourse will smooth over all rough/sharp edges.

Two Vibratory tumblers.

I first used the smaller tumbler on the right which was my dads. I could only process about 150 strips at a time.

A friend lent me the larger tumbler on the left and now I can process 5-600 at a time.

Am using five pounds of the following ceramic deburring material from McMaster-Carr in the larger tumbler.

Media for Steel, Stainless Steel, and Hard Metals, Aggressive-Deburring, Triangular, 1/4” Long, 5 lbs

Ceramic deburring media.

The vibrating motion of the tumbler causes the strips and ceramic media to continually move around each other. The multitude of tiny bumps end up smoothing all the rough and sharp edges.