View Full Version : Lofting on a Concrete floor

maa. melee
12-02-2004, 08:47 PM
Any suggestions? I dont want to lay down plywood because it will take something like 6 sheets. However, the floor is very clean, dry, and true. I can draw the lines directly full size onto the floor and somehow fair in with battens and small lead weights to keep them in place, as opposed to ice picks.

12-02-2004, 09:13 PM
Get a roll of red rosin builders paper. Tape it together on the floor and draw on that, rather than directly on the concrete. That way you can roll the lofting up and still have it to refer to if you need to later on. Easier to keep your pencils sharp too.


maa. melee
12-02-2004, 09:31 PM
Good idea. I think I'll do that. OR, I could draw on the concrete and seal the concrete so those gorgeous lines will be there long after I'm gone!

Bob Cleek
12-02-2004, 09:41 PM
Or, not that I've ever done it, but if you don't want to spend for plywood, try sheet rock. It's dirt cheap and will permit you to push nails or push pins into it easily. Nice drawing surface, too. You can also recycle it to replace the holes in the wall where you banged your head in frustration while building the boat!

12-02-2004, 10:37 PM
6 sheets of 1/4" lauan ply will cost maybe $60. Add another few for paint and strapping. It's nice to be able to drive brads or awls into it. Also nice to be able to pick it up for safekeeping or, if small enough, screw up to the shop wall.

When the boat's done (and if you don't plan to build another) paint it for the next lofting or use it for patterns.

[ 12-02-2004, 10:38 PM: Message edited by: JimConlin ]

Rob Hazard
12-02-2004, 10:47 PM
I'd go with Jim on this one. Lauan ply and a coat of paint.
Rosin paper tears and turns to mush in no time. Sheetrock won't put up with being walked and kneeled on for too long either.

A lofted drawing needs to be durable, legible, and stable until the boat is ready to launch.

12-02-2004, 11:07 PM
Originally posted by Rob Hazard:

Rosin paper tears and turns to mush in no time. Can't really agree with that. The lofting in the photo is still good after 9 years. With that said, plywood is better, but that's not what he asked.


[ 12-02-2004, 11:09 PM: Message edited by: kc8pql ]

maa. melee
12-02-2004, 11:25 PM
Rosin paper is what we use at construction sites so as not to scuff up the homeowners' pretty floors. I think that if it can withstand that kind of abuse I might be able to use it for lofting. Plus I can roll it up when I'm done, however, I've heard horror tales of paper expanding and shrinking with humidity (like everything else). Sheetrock, blueboard, plasterboard, etc turns to dust after a while and swells with humidity too much for my liking. I might use rosin paper, luan, or sheets of card (4x12')for the floor. I've never lofted before. This seems all so new to me. I can only pray I get it right the first time.

12-03-2004, 05:36 AM
While my lofting is on my plywood shed floor I was able to scounge 7 or 8 sheets of wrapping ply from cabinet shops around town...you know the places that making kitchens etc and use lots of sheets.The wrapping ply is basically junk but very useful junk,I use it to cover my drawings when I'm not using them.Its pretty thin,say 3/16", but I would think much better than paper....and free for the asking.
Peter Sibley

12-03-2004, 09:38 AM
Why not use 1/2" MDO instead of regular ply. It's schmoove one side with a brown paper facing permqanently attached, made to be outside exposed to wind and rain and snow and cold, and it's only a few dollars more than ply.

12-03-2004, 10:25 AM
Allow me to present a little logic exercise on this topic, and please forgive me if it offends anyone - edification is the intent, not insult.

1.) Most professional boatbuilders I know use plywood for a lofting floor.
2.) Professional boatbuilders are masters at doing what is necessary at the least cost to them. (Less cost = greater profit.)
3.) If a seasoned professional thinks that plywood is the solution, why should a novice believe he has better insight to the problem?

Cutting costs is a desireable ambition, but altering work methods without a reasonable experience in the process may end up being more costly than doing it the tried-and-true method.

maa. melee
12-03-2004, 11:06 AM
Im not presenting a totally new, radical idea here. Hell I could build a 3D plotter to mock up a full size boat out of baking soda, but why??? I am familiar with the "tried and true way". All I want to do is find a more economical way. I don't want to buy plywood for panking so I wont buy it for lofting. Rosin Paper is good enough for me.

12-03-2004, 11:15 AM
Have at it, sir, and best of luck to you as well! smile.gif

12-03-2004, 12:02 PM
Well, make sure you don't back it with corrugated cardboard, as someone I know did. The slight give in the cardboard was enough to tear holes into the paper whenever you kneeled on it.

Tape it straight down to concrete or wood.


maa. melee
12-03-2004, 07:25 PM
Yup its not corregated, its heavy card stock. Thanks mmd, also the rest of you. Once I get started don't be surprised to see many posts from me asking about lofting 101. :D