WéFu Filter Face Mask  Fu Face Mask variation by Cass @ Wildélan

Welcome! The main mask pattern design is from the Fu Face Mask by Joost de Cock from FreeSewing, please go there and support these folks - it’s a fantastic and simple pattern, but I’ve made some tweaks and include info in this document which I believe make the masks significantly more effective at deactivating viruses, closer to a surgical mask. Instructions for sewing and preparation follow. Step 1&2 are identical to the original Fu mask instructions, from there it changes up a bit!

Fabric Choice

You should make use of what you have to hand, but if you are able to, choose fabric that is both breathable and effective in stopping viruses. This study found that the best household fabrics or home made masks overall (for effectiveness +

breathability) are cotton pillowcase material or t-shirt material. This site shows the info from that study in a nice graphical format, too. I’ve chosen a cotton pillowcase fabric for the main & cotton t-shirt fabric for the liner. For the insertable filter, you should choose a NWPP (non-woven polypropelene) fabric. You can find this fabric in almost every home - it’s what reusable shopping bags are usually made of! The reason for using NWPP is that the middle filtration layer in surgical masks is made of NWPP. Shopping bags use a slightly looser weave NWPP than surgical masks, but it will still be more effective than cotton alone. Elastics are preferred over ribbons where available/practical - they are more secure and comfortable to wear for longer periods of time. Length of elastic required can vary a lot depending on head & neck circumference and stretchiness of the elastic, so ideally fit each mask’s elastic to the intended wearer, but if in doubt either include a little extra (the wearer can safety-pin) or use ribbons instead. The upper elastic will need to be longer than the lower elastic. For a large size mask and the elastic I have, I’m using approximately 16 inch for the upper and 14 inch for the lower elastic - YMMV! Alternatively can make elastic ear loops if you have a small amount of elastic, or prefer that way of wearing your mask.

Step 1: Join centre seam Join the curved seam that is centre of our mask by placing the good sides together and sewing them in place.

Repeat this step for both the outer (main) fabric, and the inner (liner) fabric.

Step 2 (optional): Press the center seam This step has no functional value, it will only make your mask look better. So if you’re not too bothered about that, feel free to skip it. Press the seam allowance on the center seam open so the seam lies nice and flat.nAs this is a curved seam, it won’t lay flat. But you can approach it with your iron from one side, then do the second half from the other side. Alternatively, you can use a tailor’s hem or cushion to press.

Repeat this step for both the outer (main) fabric, and the inner (lining) fabric. Step 3: Finish seams on filter insert end Next we will create the finished seams for the filter insert end of the mask - doesn’t matter which side you choose, but make sure you do it the same end of both the lining and outer (when they are placed right sides together in the next step, these seams should be on top of each other).

Ironing these folds will make it easier to sew and look neater, but it is not essential. The lining layer should just have a single stitched seam and only needs one fold, the outer layer it is better to do double (both fold and seam), though you can make do with single if you’re in a hurry.

Make sure that the amount of fabric you’ve enclosed in the seam of the main fabric layer is at least double that of the lining - you need room for an extra lip on the lining to help the filter insert to stay in place, like a tiny pillowcase cover.nFor thelining seam, make sure that you are making the fold toward the inner side of the lining.

After stitching these seams, line up the main fabric and lining, and iron (but not sew) a second fold in the lining if you have an iron - this helps make the lip on the lining more defined but is not necessary.

Step 4: Sew the outer to the inner fabric and attach ribbons/elastic Now we will sew the inner (lining) fabric to the outer (main) fabric, and attach one end of the elastics (or 2 of the ribbons if you are substituting ribbons) all in one step.

● Place your lining fabric down with the good side up.

● Then place one end of each of the elastics on the corners of one side so that they peek out just a bit from the mask, but the elastic extends inwards.

● Now place the main fabric on top of this with the good side down. You should now have both layers of your mask on top of each other with good sides together and the two elastics sandwiched between them

● Pin through elastics and layers to keep them in place

As you get some practice, you will find you don’t need to pin this and can just insert the elastics as you approach a corner. Now sew around the mask, making sure to leave one side open so we can turn the mask inside-out later. Be careful not to catch any of the elastic in the seam apart from where you want them to.

Step 5: Sew the other end of elastics & front finishing stitching including nose clip, in one final step Pull the mask inside out with the elastics to assist.

Now grab your two pieces of twist-tie (or other small wire, anything that is protected from cutting through the mask fabric can work) and twist into a shape similar to below.

Insert into the nose area of the mask, as close to the edge as possible. Pin if needed. Then pin the other end of the elastics to the top and bottom of the filter insert end of the mask. You can skip pinning once you get confident. Make sure you secure the end of the first elastic with a bit of extra stitching, then sew around the perimeter, and secure the other elastic.

Step 6: Insert filter (optional - pre-soak in salt) This is not actually a step in making the mask - but you do need it to be as protected as possible! Take your filter and check the sizing to your finished mask. Depending on seam allowance, you may need to trim the filter a little. Optional: Heat 100ml water in a small saucepan, and add approx 50g salt, with a drop of detergent added as a surfactant (this will help the salt soak into the filter evenly). Remove from heat, soak filter while water is still hot (but not boiling!) and then remove and leave to dry - salt crystals will form in the filter. Insert into the filter insert side of your mask once fully dry. Please note this is NOT guaranteed to improve the effectiveness of the mask filter, BUT there is promising research to suggest it MAY be helpful. The creator of the technique has specifically stated that “it doesn’t work like that”, but other evidence of salt deactivating viruses both internally and externally, is notable. Please see references below for more info.

Please remember: a home made mask is not guaranteed to be as effective as a commercially made surgical or N95 mask and is even LESS effective if you do not don and doff appropriately & clean regularly. Use of masks is also NO SUBSTITUTE for shelter-in-place orders given by your local authorities. Do not assume you are less at risk because of wearing a mask. Maintain careful handwashing and social distancing measures. Use of all these strategies, including masks, can help us all get through this! Stay safe! Cass @ Wildélan www.wildelan.com/masks4all/ References Home made mask fabric: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7108646/ https://smartairfilters.com/en/blog/best-materials-make-diy-face-mask-virus/ https://academic.oup.com/annweh/article/54/7/789/202744 https://www.smartbags.co.uk/blog/bag-for-life-fabric-explained-non-woven-polypropylene-nwpp https://multimedia.3m.com/mws/media/1425065O/tech-spec-3m-healthcare-particulate-respirator-and-surgical-mask-1860-n95.pdf

Salt use in masks: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0028043 ://www.nature.com/articles/srep39956 https://www.businessinsider.com.au/mask-coated-in-salt-neutralizes-viruses-like-coronavirus-2020-2?r=US&IR=T https://newatlas.com/health-wellbeing/salty-masks-kill-coronavirus/ https://www.thespec.com/news/canada/2020/02/12/the-secret-ingredient-in-this-face-mask-that-could-prevent-the-next-coronavirus-a-dash-of-salt.html Salt use to deactivate influenza viruses: https://www.google.com/amp/s/amp.theatlantic.com/amp/article/518427/ (about salt on doorknobs mainly, but also masks) https://www.elvisstudy.com/ https://www.nature.com/articles/s41598-018-37703-3 https://www.nytimes.com/2010/09/28/health/28real.html https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0028043 Donning, doffing & cleaning masks: https://www.inquirer.com/health/coronavirus/coronavirus-covid19-how-to-clean-face-masks-facemask-washing-20200407.html https://timesofindia.indiatimes.com/india/how-to-clean-and-sanitize-your-homemade-masks-everyday/articleshow/74972854.cms https://www.sacbee.com/news/coronavirus/article241798621.html More resources: https://makezine.com/2020/03/27/make-these-projects-to-fight-covid-19-right-now/ https://www.instructables.com/id/Face-Mask-Duckbill-With-Filter/ https://smartairfilters.com/en/blog/disinfect-clean-n95-mask-virus-coronavirus/? https://www.washingtonpost.com/opinions/2020/03/26/dont-panic-about-shopping-getting-delivery-or-accepting-packages/ https://www.livescience.com/how-long-coronavirus-last-surfaces.html