question about thickness of frames for zip

jhires · **Posted:** Mon Oct 17, 2011 11:50 am

It's time for me to actually start building the zip I bought plans for ten years ago. And maybe stop lurking here so much and start participating.

While looking at the materials list on the website, it says the frames are built from 4/4 stock but may be finished down to 3/4. Looking at the plans for the zip, it says frames are 3/4" thick. I took my tape measure to various places around me to see the thickness of different sized wood. I found that a 1" board from Lowes is just shy of 1/2". While just down the street, a 1" thick board from Dunn Lumber is really proud of 3/4". I could easily get 4/4 stock, but it makes more sense to me to mill 1/16" off instead of 1/4"

Those of you who have built a zip, what is the actual thickness of your frames vs the thickness of the material when you bought it?

I'm not trying to be cheap, rather far from it. Just looking to understand.

ttownshaw · **Posted:** Mon Oct 17, 2011 12:30 pm

Good Question!!!! Okay so the website gives you nominal dimensions of the lumber in the material list. The actual thickness will vary but will end up around +/- 3/4". Unless the plans specifically call out for a piece being net-net then nominal dimensional lumber is fine. Example, my chines are noted on the plans as being 1"x2" Net where the frames are just referenced as 1" material.

Clear as mud? :wink:

Now, 1/2" stuff at any lumberyard being refered to as 1" is just obscene. You'll probably find that you can buy rough cut material for less than dimensional lumber and then finish it yourself anyway.

Moeregaard · **Posted:** Mon Oct 17, 2011 12:54 pm

4/4 stock will typically have a thickness of 3/4" to 13/16." We used Philippine mahogany for our Zip build and the material thickness as we received it was 13/16." Many of the big-box stores are selling imported lumber (especially plywood), which is typically made to some metric dimension but often labeled in imperial fractional units.

-Mark Shipley

jprice · **Posted:** Mon Oct 17, 2011 12:56 pm

This might help explain it: http://en.wikipedia.org/wiki/Nominal_size

But basically 4/4 is the rough (nominal) size. After it's milled, it should be close to 3/4.

So unless the plans say 'net size' then it's assumed to be nominal. 4/4 = 3/4, 8/4 = 1 1/2", etc.
It's why a 2x4 is only 1 1/2 x 3 1/2.

Buckeyesmith · **Posted:** Mon Oct 17, 2011 1:06 pm

All my frames and battens are 3/4". The only exception is the keel, which I discovered too late, should be 1". I ended up laminating 1/4" onto the 3/4" member I had cut for the keel. Check the plans and you can measure the notches for items like battens and the keel and you can tell the dimension from that.

vupilot · **Posted:** Mon Oct 17, 2011 1:24 pm

All my frames are 3/4" African Mahogany. My hardwood supplier has racks of 3/4" thick material in lengths up to 10ft and most of it is 10 to 14" wide. That is what I cut my frames from.

Iggy · **Posted:** Mon Oct 17, 2011 3:21 pm

My first batch of 4/4 quater sawn Sapelle was milled down to 7/8" thick. It was smack-dab the same dimensions (scaled) as my Malahini patterns.

My 2nd batch has to be milled down to 13/16" as it had rougher rough-cut surface.

As I understand it, anything from 1" down to 3/4" is good.

I wouldn't use anything thinner myself. If you order from a bigger yard (like I did) that has rough stock, many of them can plane it down to thickness for you before they ship it, and in my case they also gave my 1 straight edge on each board that made it a snap to cut on my table saw later.

upspirate · **Posted:** Mon Oct 17, 2011 3:33 pm

Whatever the finished size you use, I like to cut all the notches to that exact size, that way the notches fit YOUR pieces.

I use a small slice to use as a pattern to trace the notch depth on the frames

On my boat due to cutting(milling) variance, the battens ,keel, chines& shears all came with different thicknesses, but since I cut notches to the particular piece, it all comes out fine.

Roberta Hegy · **Posted:** Mon Oct 17, 2011 4:21 pm

I also used 3/4" Philipine mahogany for frames. I used 3/4" for the chines and 5/8" for the shears which are laminated to 1 1/4". Use the plans as a guide to the actual thickness and width. Most widths are net which means actual size. And as UPSPirate mentioned, cut all your notches based on the lumber you will use so you don't wind up with notches that are too big. My keel and battens were all 1" thick white oak.

Roberta

Trackhappy · **Posted:** Mon Oct 17, 2011 4:46 pm

I rough thicknessed all my stock timber and picked the thinnest one, and then thicknessed it to the nearest standard size and thicknessed all the rest to that dimension. I did it in mm as we are metric and it was easier

jhires · **Posted:** Tue Oct 18, 2011 6:37 am

Thanks All! This really helps a lot!

A little history.
I don't really remember how I stumbled on this site, but I was first inspired by Doug Hodder's Zip build. It's nice to see so many more great examples of the Zip take shape here. I planned on starting this sooner but life got in the way (usual stuff, medical issues, divorce, marriage, etc...). Now life is encouraging me to do this. Most importantly my wife is encouraging me to do this.

So thanks in advance for putting up with any questions I may have, and especially thanks for the inspiration.

Jesse

Buckeyesmith · **Posted:** Tue Oct 18, 2011 7:27 am

Keep those questions coming. All of us enjoyed the forum support during our builds and have made forum friends as a result. Also, I miss the build process and getting to add my 2 cents on other builds sort of keeps me in the game.

Glen-L.com

question about thickness of frames for zip

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