Neat is good
There was a custom on a couple of naval vessels I served on, to take Wednesday afternoons off from the usual ship's routine--most often when at sea. This was called Rope Yarn Sunday for reasons I was never able to learn. In true naval fashion, this wasn't really an afternoon off. It was time for "make and mend;" a time to catch up on the little items that had been postponed; to fix stuff that was easily fixed; to renew lines, touch up paint, etc.
So here it is Wednesday afternoon and I am declaring this a good afternoon for such duties here. I have picked up and reorganized the tools that were scattered all over the place. I have swept out the sawdust. I have hauled away the scrap. I have inventoried materials and placed orders for needed stuff. All I have left to do this afternoon is to clean the band saw blade and report on the budget.
Budget?
Yes, there is a budget. The figure of $2,500 was deeply buried in the first post of this blog last year. That was my best estimate for the cost of this top project, as of Nov. 28, 2011. So how are we doing? Last night, after I placed an order for some monel staples at Amazon, the balance left in the hard top account was $30. An accountant would say this number is so small as to be not "material." I agree. Basically, the job is nearly done. The big expenses are already booked. And, we are still on budget.
Item Budget Actual
Item Budget Actual
Marine plywood $380 380
Epoxy, glass fabric 340 480
Scarfing tools 280 280
Lumber for bench 155 164
Fir lumber for framework 95 218
Outside labor 500 580
Trim, fasteners, handrails, paint, contingencies 250 368
Totals $2,500 $2,470
I hope this accounting is helpful, though please bear in mind that there are significant regional differences in materials costs. For example, fir lumber and marine plywood are probably a whole lot less expensive in the Pacific Northwest than they are in Georgia.
Meanwhile...
Dia and I rolled and tipped the second and final coat of un-thickened epoxy on the underside of the top yesterday afternoon. Next, we will flip it over and trim up the edges before starting to apply epoxy and fiberglass fabric to the top.
The resin coating made the top's underside about as slick as a dance floor. It is rather pretty.
The purpose of the epoxy coating is to encapsulate the plywood to prevent water intrusion which could lead to rot.
This surface will be painted, probably white, after the top is affixed to the boat.
And finally, a blog technical note...
I have adjusted the blog comments settings so that it should be a lot less hassle to post questions and comments. I sincerely welcome your suggestions, ideas, requests and questions. I will try to reply rapidly. Use the Comments section below to make a post or to read/participate in any conversations that may be going on.
Thanks for reading about this project.
Scarfing tools 280 280
Lumber for bench 155 164
Fir lumber for framework 95 218
Outside labor 500 580
Trim, fasteners, handrails, paint, contingencies 250 368
Totals $2,500 $2,470
I hope this accounting is helpful, though please bear in mind that there are significant regional differences in materials costs. For example, fir lumber and marine plywood are probably a whole lot less expensive in the Pacific Northwest than they are in Georgia.
Meanwhile...
Dia and I rolled and tipped the second and final coat of un-thickened epoxy on the underside of the top yesterday afternoon. Next, we will flip it over and trim up the edges before starting to apply epoxy and fiberglass fabric to the top.
The resin coating made the top's underside about as slick as a dance floor. It is rather pretty.
The purpose of the epoxy coating is to encapsulate the plywood to prevent water intrusion which could lead to rot.
This surface will be painted, probably white, after the top is affixed to the boat.
And finally, a blog technical note...
I have adjusted the blog comments settings so that it should be a lot less hassle to post questions and comments. I sincerely welcome your suggestions, ideas, requests and questions. I will try to reply rapidly. Use the Comments section below to make a post or to read/participate in any conversations that may be going on.
Thanks for reading about this project.
John
ReplyDeleteYour budget numbers only add up to $2000.
Question:
Will the epoxy resin allow for the hardtop to be flexible for affixing it to the frame?
Great Blog
You're right about the budget! How did I do that? Must look into it.
DeleteRe the epoxy and flexibility. We'll have the answer to that question in a day or so when I screw it down to the strongback. It still seems pretty floppy, as we move it about.
More about the budget discrepancy: I went back to my original spreadsheet and found I never made the budget side of the equation add up to $2,500. I just knew I was shooting to stay below the magic number and didn't worry about it. I could plug the table in this post to make it come out $2,500, but is it worth it? Maybe later...JS
DeleteJohn:
ReplyDeleteHi, I'm Dan, a friend of Hira and owner of WhiskyJack (mentioned in her blog along with a photo). The reason for my comment is that in my youth, I built a Brown 25 trimaran out of plywood. Something that I discovered by after I had been building for a while, and way to late, was that covering plywood with epoxy only is risky business. The epoxy itself has very little strength and the movement of the plywood, even the small amount caused by differences in humidity throughout the year caused minor cracks to develop in the epoxy skin. And small cracks let in moisture which allows the wood to grow and shrink which propagates the cracks. Soon enough the epoxy will look bad. A solution I was made aware of (after I had assembled most of the boat) is to to use a very thin fiberglass cloth between one of the layers of epoxy (second or third but not first layer) to add enough (shear) strength to prevent the cracking described above.
Just sayin'.........
Keep up the good work!
That's a good point, Dan, and one I wish I had thought of sooner. There will be fiberglass cloth on the top side of the top and I plan to carefully seal any piercings off the epoxy/glass cloth outer plywood skins. Then there will be paint on top of everything. I think that is all I can do at this stage of the game.
DeleteOh! One other thought that may be relevant. The kind of epoxy I am using is a "high viscosity" variety. It is said to penetrate plywood, rather than just lay on top
John:
DeleteThe paint layer will help a lot. High viscosity is good. Most epoxies penetrate wood well due to their longer cure times over other resins. I used Gougeon Brothers West System epoxy mixed "thin" with a long cure time to allow for penetration. I always did a "saturation coat" on the bare wood followed by light sanding before doing anything else.
I used the "dry" method described here: http://www.westsystem.com/ss/applying-cloth-tape/ and found at least one, and most of the time two, additional layers (sanding between coats) of epoxy were necessary for a nice smooth surface. I also mixed aluminum powder in one of the final coats to make the boat "radar reflective".
Best of luck.
dan
Dan: I am a longtime student of the G. Bros. I used the dry method to encapsulate the half-round and top edges on the current project. Also did one-coat, sand, add second coat on the underside. Radar reflectivity-- an interesting idea. How did the aluminum dust effect paint coating color and durability?
Delete