The ASL sign for BOIL is produced by the non-dominant hand in "open-B" handshape with the palm facing down in front of the body. While the dominant hand is underneath the non-dominant hand with the fingers wiggling except the thumb.
Memory aid: Think of your dominant hand as the "flame" and your non-dominant as the "surface."
The sign for BOIL can also be used as an idiom to mean ANGRY / BURNING INSIDE / BURN INSIDE / BOIL INSIDE / FUMING EMOTIONALLY / BOILING MAD
Another version of showing anger is "BLOW-TOP" meaning lose temper / anger boil over
If you want to describe the act of 'boiling water' and the water is simmering you could sign:
If you are referring to "BOIL" as in "blister" you could use a CL and fingerspell B-L-I-S-T-E-R or just fingerspell.
Notes:
See: HOT
Notes: