Quickie hard top project

[erikgreen]

Re: Quickie hard top project

Not a bad idea. I do have a nice vacuum pump I've been wanting to try though, so I'll probably go through the effort with that. After I get clamping working with it I want to try vacuum infusion, which will be handy for making fiberglass parts in molds... so useful for a lot of things.

Last night I took a couple more pics, but I ended up just getting the steel frame tacked up and fitted to the bottom of the top. I have a bit more to go on it, but it fit the first time, so that's good. It does show a bit more than I'd like on the sides of the top, so I may find a way to extend the sides a bit.

I ended up using 1.5" square tubing in 11 gauge for the 5 foot sides and 14 gauge 1 inch round for the cross bars. Plenty strong and a half, I should be able to walk up top when it's done. Weight isn't too bad... I'm aiming to have the whole top weigh less than 100 lbs when done and the frame weigh less than 150... that's peanuts compared to the weight of the whole boat.

More work tonight.. I also found out I'm not taking the boat out this weekend due to time limitations, so I get to spend all day friday working on it. I'll try to finish the top frame, plus I need a boarding ladder, a walking plank on the trailer, the final sanding on the primer of the top, first coat of paint... I find something new to do each time I turn around, and it's all fun.

Erik

 

[jonesg]

Re: Quickie hard top project

The worst thing about these DIY projects is
the lack of instructions ( which I usually ignore anyway) .

 

[Mark42]

Re: Quickie hard top project

Hey pretty neat! I don't know how I managed to miss so many updates on this project. Looking good. Of course, anything that requires 100% fabrication always takes 5 times longer than planned (as opposed to installing pre-made components that only takes 3 times longer than planned )

 

[erikgreen]

Re: Quickie hard top project

Okay, time for a few more pics.

I spent a bit of time last week getting the edges of the wood glassed over. It didn't work too well, the usual problems of getting fiberglass to turn corners. But it was an experiment, so that's ok. I tried sand bags, clamps, and a few other things but in the end I still got bubbles.

While sand bagging, I was really hoping my neighbors wouldn't look in the window... that would make for some awkward questions about the ziplocs full of sand:

So I cleaned up the bubbles with a utility knife and made sure the edges of the wood were protected in each case, which is what I really wanted.

I should mention at this point that I had gotten the top side basically flat, with few visible areas that needed more sanding, using a red guide coat (I had some spare red spray).

I did fill in the low spots I found ... but I had run out of microbubbles, and I had to use a little wood flour, with plastic on top to ease the fairing job:

Then I took it outside to primer it. In doing so I found a few more places that needed sanding. I'll fix those before I prime again and paint.

But since I had it outside I took a bit of time to clean out the workspace. Then I leaned the top against the wall to measure the size of the support tubes... I got some steel 14 gauge round tubing to use, and I already had some square tubing. I fitted the square tubes to the 5 foot sides and used the round to cross. I tacked the tubing in place and checked the fit:

So far so good... I got the measurements right. The top will actually be supported by the square tubing, that rests on mahogany pads at the end of the cross members that are encapsulated in glass. I'll weld on tabs to screw into those.

The two front cross bars I placed so they more or less match the "ribs" and can be attached with tabs for extra support. The back tube I decided I wanted a bar near the rear to attach a grab bar to that would stick out the back of the top.

After checking the fit of these parts I made a diagonal support for the "peak" at the front of the top. A bit tricky because the shape I gave the top meant that the peak wasn't in line with the sides.

I first made a center piece out of sheet to weld the ends onto:

The flat sides will mate with the underside of the top and the back side of the forward edging. I'll probably just glue them to the top with 5200. This piece also provides a weld attachment point for two diagonals from the front legs.

I measured and tacked the diagonal supports in place... I had bought some half inch square tubing for this since not much strength was needed, just stiffness:

Then I fitted the front piece in place (altering the angles you see here since they weren't even) and checked everything before finish welding the sides to the cross bars and the center support above to the diagonal supports.

I haven't welded the diagonals to the side bars yet, I'll wait until I can fit it to the frame and top again to be sure I have the angles right.

Now that I have the frame built I can start on the legs using measurements from the boat and the top, and I can simultaneously work on finishing the top itself. I put it on sawhorses to do that... looks pretty good at this point, even with the thin coat of primer and the guide coat showing through here and there:

Today I'll be sanding the top some more and getting the last uneven areas out, then finish sanding with some 120 grit and 240 grit. I'm hoping I can get a fairly shiny finish, and I'll be using one more coat of primer and two coats of paint, and sanding in between. Should be interesting.

Oh, and before that I need to put in place pads to mount things... antennas, horns, etc. I figured I may as well do that and fair them in before I paint it. I'll be using small sections of mahogany so I can screw into the wood and still not get much rot.

I'll also be gluing a piece of headliner fabric to the underside.

Then I'll be working on the legs and attachments to the boat.. I might just weld flat plates to the tube ends, but I'd like the thing removable....

Erik

 

[jonesg]

Re: Quickie hard top project

Are you keeping track of the weight?
Square steel tube, here comes the weight.

I just put my top on a toledo scale and the composite top itself is 36lbs,
haven't weighed the top tubing frame but I'd say its the same.

So if my all up weight is around 80lbs for 7 feet x 5 feet top how does that compare to a plywood top.

another idea, too late, for glassing that ply top would have been to add half circle beading to the edge, the glass will go around that.
Or run a router along the edge.

or an even better idea, again too freakin late,

take 2 steel angle irons, as long as the edge you need to glass,
wax the angle iron and lay cloth inside it add resin and clamp the other angle iron to it,
squeeze the clamps tight ,
when the resin sets pop the glass out of the irons and you have a preformed corner to glue on your wood edges,
then glass over that just to the edge.
No need to take the glass cloth around the outside curve.

 

[erikgreen]

Re: Quickie hard top project

Yeah, good ideas. I still might extend the sides a bit more with a butt jointed skirt piece, to hide the support tubing some more. Don't know yet, I'll see how it looks when I get the top of the legs the first time.

Weight so far of the top is about 70 lbs, weight of the frame so far is about 30 lbs or so. I'm hoping to keep the whole top and frame assembly less than about 225 pounds. Keeping in mind that it'll be strong enough to walk on, that's not too bad.

The boat itself weighs about 3500 lbs empty, so adding 225 lbs about 8 feet above deck is acceptable, although obviously the lighter the better.

Erik

 

[erikgreen]

Re: Quickie hard top project

Quick update on this.... I've been driving the boat all summer, and for the last couple weeks doing repairs on my sterndrive, lower shift cable, bushings, and electricals. I also put some Bennett tabs on my boat salvaged from another boat, and I really like having them. But it's taken time away from my projects.

Right now I'm painting my sterndrive and trying to get a new shift arm installed in my bell housing.

I'll hopefully get back to this very soon. I did find and paint some brackets for attaching the tubing to my top cap... I'm too cheap to buy stainless ones for now. Basically they're heavy steel angles, and when bolted on to the top cap with a backplate they'll more than take the stress of the top. As a bonus they're nicely curved and match the angle needed just about perfectly.

The top is painted and has sat outside... rain runs off it really well, but it's picked up some dings and scratches in the paint... I think it took a month to fully harden, and in that time it was vulnerable. Next time I'll use a different paint I think, like Perfection or Awlgrip or something that's two part. It did come out nice and glossy, and next time I'll spend even more effort on getting the surface smooth and fair before painting.

I built the steel tubing frame, it came out ok. But then testing the top on it I discovered I'd made it 3 inches too wide! And that was after working on the frame for 6 hours straight and giving myself a nasty burn in the process. Turned out I had got the measurement right but forgot to account for the tubing width.

So I need to take the frame back in the garage, cut it narrower, re weld, maybe add one more tube, then sand the whole thing and neaten it up some. By that point I should be ready for a test fitting again, and if the top fits the frame I'll weld on the lugs/brackets for the bolts, paint the frame, and fit it all together.

Whew.

Too many projects, not enough time.

Erik

 

[redfury]

Re: Quickie hard top project

I hear ya on the too many projects thing Erik! My boat has been put on the back burner while I prepare for winter . My lawn tractor took a dump on me, the snow blower won't start and my beautiful stringer glass job is garbage....delaminated from the hull, so I have to grind out that glass and reprep it and glass it again! So much for hoping to get the floor in this summer. I'll be lucky if I get the stringers finished .

That top looks really nice though. I don't know how many times I haven't accounted for the thickness of the material I'm working with...it's a stupid mistake, but why do we still make it when we are aware of it happening from time to time?!

 

[erikgreen]

Re: Quickie hard top project

Well, I think my guess is that I get into a "death march" trying to get things done, and by the time I've worked for 6-7 hours on boat stuff I should knock off instead of doing more to "try to get it on the water".

I should have learned my lesson in college, writing computer programs. I'd look at my late night work the next day and say "what the flip was I thinking?"



Erik

 

[allpoints360]

Re: Quickie hard top project

a stupid mistake, but why do we still make it

I cannot tell you HOW MANY stupid, mindless, careless, idiotic, lame-brained, bone-headed, stupid (did I already say that?) errors I've made trying to just get something DONE. ESPECIALLY with glass. OMG!

Just this Tuesday, I wanted to get a filler coat of duraglass on a big patch job before dark. I laid it out flat and beautiful! Came back the next morning... soft cure. Argh!! Now I've got to scrap it all down and take twice as long... and I know I know better.

I think I know, but sometimes forget, the thing about it is, you just gotta give it the time. And you can't hurry time.

Disregard this post as necessary. Nice top, Erik. Good luck.

 

[Tiwaz]

Re: Quickie hard top project

So how did this ever turn out? Any pics of it on the boat?