The weight of paint

Discussion in 'Boatbuilding' started by Frosty, Aug 4, 2011.

  1. Frosty

    Frosty Previous Member

    A gallon of paint can be pretty heavy, as a cat owner I am always concerned about weight.

    Burnt paint scraped off and swept up off the floor seems to weigh much less that it did in the can. I assume that most of the chemicals that make it liquid evaporate off.
    Has anyone made measurements of this.
     
  2. CDK
    Joined: Aug 2007
    Posts: 3,324
    Likes: 145, Points: 63, Legacy Rep: 1819
    Location: Adriatic sea

    CDK retired engineer

    An unfair comparison Frosty.
    The burnt paint has lost most of the resin as well as the thinner that gave it the proper viscosity for a brush or roller. Burnt paint is mainly pigment and some inorganic filler.

    Paint advertised as "high solid" has approx 60% solids, so still 40% liquids. Normal paint left in an opened can in the sun will loose more than 50% of its volume. Remaining weight will be more than 50% because some fillers like zinc are very heavy.

    But I doubt your boat can sink from too much paint...
     
  3. gonzo
    Joined: Aug 2002
    Posts: 13,611
    Likes: 382, Points: 93, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    The VOC content information is in the can. You can easily calculate what percentage of the weight will evaporate when the paint dries.
     
  4. Submarine Tom

    Submarine Tom Previous Member

    Now if you were transporting gallons and gallons of paint, this would be a different matter.

    -Tom
     
  5. Fanie
    Joined: Oct 2007
    Posts: 4,603
    Likes: 170, Points: 63, Legacy Rep: 2484
    Location: Colonial "Sick Africa"

    Fanie Fanie

    Perhaps Frosty, you should indicate just how much paint you intend to put on the boat !

    How many gallons have you in mind ?
     
  6. hoytedow
    Joined: Sep 2009
    Posts: 5,402
    Likes: 194, Points: 73, Legacy Rep: 2489
    Location: North of Cuba

    hoytedow Wood Butcher

    Attached Files:

  7. Fanie
    Joined: Oct 2007
    Posts: 4,603
    Likes: 170, Points: 63, Legacy Rep: 2484
    Location: Colonial "Sick Africa"

    Fanie Fanie

    Cats don't have 'owners', they have servants :D
     
  8. rwatson
    Joined: Aug 2007
    Posts: 5,839
    Likes: 276, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    One of the US team in the 'Little Americas Cup' some years ago had a dull grey paint job.

    After the undercoat was put on and polished, the skipper couldn't see the sense in applying another 25 kilos of bright topcoat.

    I think they won that year.
     
  9. Frosty

    Frosty Previous Member

    Yes ive seen racing boats with bare epoxy on the inside you can see the sea passing the hull. The weight of paint is an important consideration in such circumstances in a boat where crews underpants are weighed along with anything else in your personal belongings.
     
  10. Landlubber
    Joined: Jun 2007
    Posts: 2,640
    Likes: 123, Points: 0, Legacy Rep: 1802
    Location: Brisbane

    Landlubber Senior Member

    Gonzo has it right, simple to work it out....the solvents go to heaven and the rest is the weight on the boat, or if you are Boston, the solvents go into polluting our already getting hotter planet......
     
  11. whitepointer23

    whitepointer23 Previous Member

  12. hoytedow
    Joined: Sep 2009
    Posts: 5,402
    Likes: 194, Points: 73, Legacy Rep: 2489
    Location: North of Cuba

    hoytedow Wood Butcher

    It's going to be a cold winter.
     
  13. Boston

    Boston Previous Member

    I always appreciate an honorable mention ;-)
     
  14. Frosty

    Frosty Previous Member

    Ok lets look at this Gonzo says look at the VOC--now I dont know what that is so dont laugh if I guess it as Volume of can so what does that mean.
     

  15. jehardiman
    Joined: Aug 2004
    Posts: 2,480
    Likes: 199, Points: 63, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    VOC = volatile organic compounds, i.e. the solvent that evaporates away leaving just the solids. Normaly expressed in lbs per gallon (gm per ltr) or as a percentage of total "wet" weight.

    For what it is worth, paint, welds, and fastenings account for 5-7% of the total lightship weight of a steel ship. Not sure about the precentage for a wood or composite hull, but I'd guess 2-4% of lightship based upon the weight of the bottom paint I used to put on my Ranger 26.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.