Anchoring the Building Form…or Not

Topics not covered by another category.

Moderator: Bill Edmundson

Post Reply
User avatar
Ibrew2be
Posts: 131
Joined: Sat Aug 03, 2013 4:52 pm
Location: Cincinnati, OH

Anchoring the Building Form…or Not

Post by Ibrew2be » Mon Jun 03, 2019 5:49 pm

I am getting down to brass tacks in trying to figure out how I will manage to build an 18 ½ foot boat in a standard suburban 2 car garage that measures 20 feet front-to-back. I have the luxury of using the whole garage, so that allows me the option of positioning the build on an angle thus helping the space challenge a bit. I’d like to maintain the option of being able to work with the garage door closed, since in early spring and late fall in these parts (southern Ohio), it could be warm enough to work in the garage some days if the door were closed, but not if it were open.

I have always thought that I would want to have the building form securely anchored to the floor. My thinking has been that this would facilitate ensuring that the form is rigid, level, plumb, and square, and I could tweak and shim things as needed to compensate for the slope in the garage floor. Alas, with the form anchored to the floor and the garage door closed, it would make for a very tight fit when trying to do work at either end of the boat.

A possible solution to this dilemma would be to have the building form on a platform with casters. That would allow for moving the form around at least a little, generating some needed elbow room. I know that there are builders on the forum who have used this movable platform approach. But my question for you is, how have you managed the need to keep things level, plumb, and square if the platform is moving around on a floor that’s not level?

Barry
Barry Shantz

Imp built and launched. Thinking hard about Boat 2.0

TomB
Posts: 664
Joined: Wed Jan 18, 2017 4:07 pm
Location: Holland, MI

Re: Anchoring the Building Form…or Not

Post by TomB » Mon Jun 03, 2019 6:44 pm

Ibrew2be wrote:
Mon Jun 03, 2019 5:49 pm
how have you managed the need to keep things level, plumb, and square if the platform is moving around on a floor that’s not level?

Barry
Hey Barry,

Level, plumb, and square are very important, sure. I would add rigid to the list, and for a movable form, I think rigid is maybe most important. When you get down to it, level plumb and square is about the relationship between the components, how this relates to that, not how it relates on the planet. So if you get rigid, then level the form, square frames to the form and get them plumb, and lock them down so they can't shift, then the relationships are set and it won't matter if the frame is down an inch at one end after you move it. That said, mark the floor so you can get the casters back in position and you can double check during the build.

Tom

Hercdrvr
Posts: 1007
Joined: Mon May 11, 2015 12:52 pm
Location: McKinney TX

Re: Anchoring the Building Form…or Not

Post by Hercdrvr » Mon Jun 03, 2019 8:43 pm

I’m on my 3rd boat, all of them constructed on a rolling building form.
Matt B

neel thompson
Posts: 1368
Joined: Fri Oct 01, 2010 2:33 pm
Location: Collegeville, Pa

Re: Anchoring the Building Form…or Not

Post by neel thompson » Tue Jun 04, 2019 2:34 am

Barry,,,, I constructed my building form for my PB 22 with swiveling castors. I anchored it to the concrete garage floor in four corners and kept it there until I had the first layer of ply on. Then I removed the floor bolts to allow me to move the hull. My feeling is that you should anchor it as Tom said and keep it there as long as possible. Best of luck to you as you move ahead.... Neel
Attachments
20180423_124442.jpg
20180414_135657.jpg
20180418_103818.jpg

User avatar
Jimbob
Posts: 763
Joined: Thu Jul 25, 2013 1:07 pm
Location: Sacramento, CA

Re: Anchoring the Building Form…or Not

Post by Jimbob » Tue Jun 04, 2019 9:51 am

I built my boat on a form that was not bolted down to the garage. The form was square in every respect, and very rigid. Initially the form just sat on the garage floor, the floor was flat so the form was not tweaked. If your floor is not flat, you could use shims so that your form stays true. I was able to drag the form around as work progressed. After the plywood was added to the hull I needed more room so I added casters to the form so that I could move the whole works out of the garage if I wanted to. I didn't level or make the form plumb to the garage floor. I relied on squares and accurate measurements during the build. The way I looked at it was when I previously built furniture or cabinets in the past it was never level or plumb to the floor, I used squares etc. My boat came out with every thing in perfect alignment.
Jim
Attachments
Before casters.
Before casters.
Casters added later.
Casters added later.
Jim Neeley
Building a Barrelback in Sacramento, CA
viewtopic.php?f=15&t=28089#p172969

User avatar
Bill Edmundson
Posts: 11684
Joined: Wed Nov 23, 2005 6:45 am
Location: Birmingham, AL, USA
Contact:

Re: Anchoring the Building Form…or Not

Post by Bill Edmundson » Tue Jun 04, 2019 1:27 pm

If your floor if not flat, once you have the form square and flat mark the floor where the corners of the form belong.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

TomB
Posts: 664
Joined: Wed Jan 18, 2017 4:07 pm
Location: Holland, MI

Re: Anchoring the Building Form…or Not

Post by TomB » Tue Jun 04, 2019 3:50 pm

Hey Barry,

Here are a few more thoughts...

Using Neel' form as an excellent example: increase the long members a size or two so they can't flex when you stand on the center; the plywood on the vertical forms keep that section from racking, extend it down so it helps prevent the long direction from racking too; add elevator bolts to fine tune the level of the frame; a dab of hot melt glue or cheap caulk between the elevator bolt heads and slab will keep the form from sliding around (hot melt can be chipped off when no longer needed and naphtha or acetone will soften the caulk; a bit of cord or bungie wrapped around the caster will keep them from rolling.

Tom

hoodman
Posts: 2255
Joined: Thu Nov 10, 2011 8:48 am
Location: Lafayette, IN

Re: Anchoring the Building Form…or Not

Post by hoodman » Tue Jun 04, 2019 4:18 pm

I bolted mine to the floor with sleeve anchors because that's what it says to do in the book and on the plans. If you make a rolling form it will need to be much more substantial than what is in the plans. Good casters aren't cheap either. A rolling form will allow you to tuck the frame away as much as possible when you need room to scarf the longitudinals and cut out your hull planking.
Matt

Building a Geronimo......!
viewtopic.php?f=2&t=25139

User avatar
Ibrew2be
Posts: 131
Joined: Sat Aug 03, 2013 4:52 pm
Location: Cincinnati, OH

Re: Anchoring the Building Form…or Not

Post by Ibrew2be » Tue Jun 04, 2019 5:59 pm

My thanks to everyone. There is a lot of good advice here.

Tom and Matt's point about the need to ensure that a movable form is substantially built is well taken. Neel, I like what you did with the plywood to keep things from flexing, and the idea of anchoring things initially, then allowing free movement later. Jim, thanks for the pictures. You've provided a reminder that bolting things together, rather than screwing them together, is a more robust approach.

Barry
Barry Shantz

Imp built and launched. Thinking hard about Boat 2.0

Hercdrvr
Posts: 1007
Joined: Mon May 11, 2015 12:52 pm
Location: McKinney TX

Re: Anchoring the Building Form…or Not

Post by Hercdrvr » Wed Jun 05, 2019 4:11 am

A point about my mobile rolling forms, I don’t start rolling the boat around until the frames have chine, sheer, keel and battens firmly secure to all the frames. It’s pretty rigid at that point.
Matt B
Attachments
All Brakes are parked on casters at this stage
All Brakes are parked on casters at this stage

User avatar
Ibrew2be
Posts: 131
Joined: Sat Aug 03, 2013 4:52 pm
Location: Cincinnati, OH

Re: Anchoring the Building Form…or Not

Post by Ibrew2be » Wed Jun 05, 2019 4:15 pm

Makes sense. Thanks for the clarification, Matt.

Barry
Barry Shantz

Imp built and launched. Thinking hard about Boat 2.0

Post Reply

Return to “Miscellaneous”