Muratic acid (hydrochloric acid) will remove the husks and is commonly used
for the purpose.
For the DIYer a garden sprayer works well for application; be careful to
adjust for a spray, not a mist which would drift in wind. Using on a calm
day is simply common sense of course, as is not applying it to your metal
gear (plastic masking works to prevent that). Wear rubber gloves,
throw-away clothes and definitely goggles since no matter how carefull you
are there will always be a little bit that gets on you, and as with anything
accidents can happen. However it's not going to be a major problem if some
gets on your skin, keep a water hose running to wash it off. This is not
the same as something like sulphuric acid. Wearing a mask would be a good
idea, since the fumes are noxious; but I don't and am just carefull to stay
out of range of any fumes.

Neither "super dangerous" as knee-jerk alarmists would have you believe nor
an environmental problem in the quantities we're talking about (yes if a
tanker truck spilled, but very limited in scope). Widely used for many
purposes such as etching concrete to prepare for painting or other surface
treatments, for adjusting ph balance of swimming pool water, etc. It's the
active ingredient, in dilute form, in many household chemicals for drain
cleaning, lime removal, etc. Sold at the hardware store in gallon jugs.
Cheap. If you dump a gallon on the ground the worst that would happen is
that it would kill the vegetation in a limited area and raise the ph value
of the soil a little bit for a short while. Other forms of acid work better
for adjusting soil ph value longer term and are commonly used to do so.

Chuck H

"Leroytjr3" wrote in message
...
does anyone have a suggestion on how to remove barnacles and husks from a
fiberglass hull. have already scrapped barnacles but husks remain. any
suggestions on the best way to remove?