[Maintainer's note: This method is probably the most hazardous to your health. Follow *ALL* safety precautions. Following alternate methods of headmaking is suggested. Due to this, the builder is on their own when searching for celastic.]

Safety procedures - Please read the section on respirators and safety glasses.

Another writeup on using celastic from Schenz - http://www.schenz.com/fm_celastic.html

MSDS on MEK - http://www.freemansupply.com/MSDS/Freeman/HardwareAccessMSDS/CelasticSolvent.pdf

From: Buster Bunny
Subject: Re: OHIOFUR: Fursuits

1. make a actual size clay sculpture. Be sure to reduce it by 1/2 inch so that when the finished fur is on it that it wont appear out of porportion.

2. Wrap the clay sculpture with plastic wrap, Be sure it is stretched very tightly over the clay. Leave no air bubbles.

3. Spray the plastic wrap with WD40 lubricant. (This will prevent the formfast from sticking to the plastic wrap.)

4. Cut your formfast into small strips of 10“ long by 1.5” wide. Be sure the ends are cut at 45 degree angles.

5. Place the MEK (chemical solvent) into a coffee can that you DO NOT plan to use again. Only fill it 1/4 of the way full.

When working with MEK be sure to also wear EYE PROTECTION. This stuff gets in your eyes and you're done.

6. Dip one strip at a time into the solvent and apply them starting at the top center of the head. Overlap each strip by at_least 1/4 to a half width of each strip. Repeat this until the entire head is covered. Be sure to smooth out the strips as they are applied (USE CHEMICAL RESISTANT PLASTIC GLOVES WHILE DOING THIS & WEAR A RESPIRATOR MASK DESIGNED TO PROTECT AGAINST MEK.)

7. Allow the head to dry for 30 minutes then repeat step 6 again.

8. After you have two layers on the mold, Allow it to dry for 2 days before continuing to the next step.

9. Draw in pencil where the eyes and fur color contrasts will be. Also mark with a dotted line where you will be cutting the formfast to remove it from the clay scultpure.

10. Take a hacksaw or a power hand held grinder with a round wheel and cut up along two sides of the formfast, Be sure NOT to cut it completely in half.

11. Once the cuts are made pull it off the mold. Don't worry about bending it. It will flex alot before it will break. if you hear splintering, Do not pull it apart anymore. Rather remove the clay a little at a time.

12. Once off the mold get some duct-tape and tape back the cut areas immediately. The formfast will lose its shape if the next steps are not done quickly.

13. Dip more formfast strips into the solvant. This time make the strips 2“ in width. Apply it over the cut lines and put at_least 2 to 4 layers over this part. Be sure to overlap the cut area by 4” each side for maximum durability.

14. Once the one side of the cuts are done AND DRY, turn over the formhead and do the same thing to the other side of the cut lines.

15. Again allow the formfast to dry for 24 hours before continuing.

16. Cut out the eyes and mouth or any other ventilation areas. Apply screen or other mesh material for eyes and mouth. Drill holes for head gear and cover with fur.

You're finished! :)

MEK is also the primary solvant used in Polyurethane paint.

Another point I want to stress. BE SURE to get CHEMICAL resistant rubber gloves. MEK can AND will eat though most other types of plastic upon contact. Soft rubber is not effective enough aginst this chemical. If you are unsure how to handle it please contact the manufacturer, OSHA or the EPA before using it. It is highly dangerous and flammable. That is also the reason I stress you should do these only with someone who has experiance with formfasting. They have the equipment and the knowledge of the materials used.

There is a special kind of respirator that can be used with MEK. It has insert cartridges that filter it out. They were released in 1992. When I was in the Airforce and handling these chemicals, These masks were required by OSHA and they were of a specific nature. Normal masks will not protect you. This is a specially made cartridge.

I've personally been exposed to this chemical so much that I have built up a small reistance to the effects of the fumes. But I do strongly recomend doing Step 6 in a very well vented area.

If anyone has questions reguarding this chemical or conserns for that matter please feel free to ask me.

[Maintainer's note: This respirator can be found at the local hardware store.]

From Bob Repas, on the subject of respirator masks with formfast:
I wish to point out that a respirator mask does NOT protect against fumes given off by the methyl-ethyl-ketone (MEK) solvent. They are for particulate filtration only. Be sure to perform this step in a WELL ventilated area with plenty of fresh air. A garage with the main door open and a big breeze box fan to promote circulation would be ideal. Not something you want to be doing in your basement in the middle of winter. :}

From: Dave Ellis, in response to what Bob Repas wrote above;
There are some TRUE respirator style masks out there that can filter the fumes out. Just make sure you get the right one. Particulate or dust masks are TOTALLY INEFFECTIVE with fumes. Look for one that specifically states it is for fumes and vapors. Most use some sort of chemical filtration in the form of canisters. Some of the larger and better home improvement stores have them in stock or look under safety equipment in the Yellow Pages. If you are planning to do this regularly be sure to invest in a good unit. It may literally save your life later.

Even with a respirator mask, definitely follow Bob's instructions to do this in a well ventilated area. I'd even add a fan or two. MEK is used extensively for furniture stripping. As you can well imagine, anything whose vapors can strip paint, varnish and anything else off furniture will eat up your nose, throat and lungs as well. It is also carcinogenic. So make sure it does not come into contact with your skin by using thick rubber gloves like those sold for furniture stripping, not the lightweight latex gloves. (I'm not sure, but I *think* MEK dissolves latex gloves anyway.)

From: Rex
Buster bunny wrote:

Oh! I almost forgot to mention.. When working with MEK be sure to also
wear EYE PROTECTION. This stuff gets in your eyes and your done.

Argh, I cringe at even saying anything about this thread, However I will anyway. First off, know what you are doing and the properties of your materials before you begin your project. This would include reading an MSDS to see what kind of filtration and other protection is needed. Second would be to make sure the safety equipment is not expired. Even though you might have the proper mask and filter, please be aware that those filters have a shelf life and once opened can only be safely used for a certain period of time. So that mask you might have bought a couple of months ago may not afford much protection if new filters are not purchased. Plus there are different kinds of filters with specific properties for certain chemical protection. Please also note that you can not become immune to chemical fumes…you may be tolerant of the fumes, but damage will still be done to your system.

Any questions of safety should be directed to your local fire department as they should have a haz-mat section. If not they should be able to direct you to a local fire protection safety store.

Also, if you are going through the trouble of dealing with the chemical hazard, why not just make the stuff out of fiberglass? That way you could use the materials for other projects. It is MEKP in fiberglass unless you use epoxy resin.

From: “Buster Bunny”
There is a new addition to the proper handling of that chemical MEK. Filter masks are NO LONGER approved by OSHA to be used with this chemical. Forced air resperators are the only approved saftey handling equipment for it now. The fumes from the chemical destroy the air bag tissues in your lungs and will cause cancer in the long haul. If you plan to do a formfast head, PLEASE contact me before you start your project. I can help!