Glen-L 21' Canyon Cruiser - Aluminum

[sprintst]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Major progress. You're making it look too easy.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Major progress. You're making it look too easy.

Thank you. I won't tell you it's easy but it's not beyond anyone that has a little insight as to how boats are built. I'm finding that the resto's I did really prepared me a lot better for this than I had imagined.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

The next step is to build out the frames with flanges. After thoroughly reviewing the plans, this particular task will have to rank as difficult. I started with frame #3 because it seemed like a good place to start.

The flange is 1/4x1-1/2" flat bar that is set on the inner edge of the frame. That's all the info you get in the plans but after reading everthing again there was really only one logical way for it to be fit up. It would have been nice if this was made a little more clear but I can see how it would be hard to do.

On Frame # 3, I left the bar stock long at 12 feet, found the center and then lined it up and marked where I thought the bends should be. I then bent it and worked through my errors by clamping and heating, it turned out fine but I fought it all the way.

On Frame #4 I tried a different method of not pre bending the flange and instead found center and began clamping and heating to form the bends. It doesn't take a lot of heat to soften 6061-T6 Aluminum and the curves were actually quite easy to form. It took a ton of clamps and there was a lot of frustration as they tended to slip off and drive you nuts. However, I would recommend this method for someone that didn't have a flat bar bender. It was better but still a fight.

On Frame #2, I decided to put on my fabricators hat and re-layout the frame. I then took measurements from one side, added the numbers together and multiplied by 2. I took the cuttoffs from frame #3, measured them and then subtracted that from 144 (12 ft) and lo and behold I was dead on.

Here is a pic of the frame clamped to my fabrication/welding table. Notice the use of lumber to raise it raise it off the table. This supports it fully on the smaller table top.

I mentioned in one of my earlier post that the 1/4" plate is cut from a roll and then straightend by the vendor. Here's the result and the reason that the flanges are added. This is not a photo illusion, its actually curved that much!

To re-establish the layout lines that are true to the cut just lay your straight edge along the inside edge of the frame and continue the line onto the area that you need to establish.

The first order of business is the scariest. Cut the flat bar to length. I was really reluctant to do this since I have my materials figured pretty closely. I gained confidence by realizing that I would likely be able use the material somewhere else but I didn't want to find out I was off by a quarter inch after going through all that bending. Still, I forged ahead and it worked out fine.

In the previous photo you can see the flat bar clamped to the table edge. This is all you need to get the first bend. The two 9" radius's need to be done on something like this.

When you bend a long radius like this, you bend from point a to point b but you do so in small increments and pretty much guess. You'll make a couple of trips back to the frame pre fitting until you get it where you want it.

Once it's all bent, clamp it to the frame to check the final fit. Oh, did I forget to tell you to go buy at bunch of clamps?

.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Welding the flange to the frame.. This is probably the easiest part of the job. Once the frame has been pre-fit, take the clamps off and wash the aluminum pieces in Dawn dishwashing liquid that has been chilled in a refrigerator. ??????? What's that all about, you say???

All soaps contain parafin. It's what gives you that squeaky clean feeling. It's not what you want on your metal if your welding and chilling it congeals the parafin so all that comes out of the bottle is detergent.

Once you've washed it you need to acid etch the mill slag off of it. I bought a gallon of Alumaprep 33 for 25.00 and a quart of Arcair prep for 25.00. After a thorough testing, save your money and buy the Alumaprep 33. They both work exactly the same.

Use a green scotch brite to scrub the metal while the acid works (were rubber gloves). After two or three minutes re-wash the metal with Dawn soap to stop the etching and then rinse it thoroughly and dry it. Dry it with a towel since water has minerals that will form deposits and you'll see it as little black spec's in your welds.

Now use a right angle die grinder with a green scotch brite pad and go over all the areas that welds will be made. Blow it off with dry air and then wipe it down with acetone. Now you're ready to clamp it up again.

Ye gad's look at all of those clamps. I'm tig welding these so I need a good tight fitup. The trick is to feel the underside with your finger tip and make sure the edges are flush. If they're not just tap it with a hammer until they align. This will ensure that the flange sits at a right angle and most importantly, this will straghten out that curve in the frame.

You simply lay down about a 1" tack weld every 6" or so, (more often if you want). Then you remove the clamps and re-clamp the next area. You want to move from one side to the other so that the bar is sort of flowed out to the other end. You may need to trim a little of the end when you get done but that's o.k.

Here's a shot of it all tacked up. Once all the flanges are fitted and tacked on all the frames that need them, I'll grind down the tacks and finish weld it all around. The plans only call for intermittent 2" welds and that's probably fine if you don't feel like doing the extra work, it's just something I want to do.

Plan on the bending and welding process to take about 5 hours per frame if you take your time. This is not a easy as I make it sound in this post but it's not horribly difficult. You may choose the trial and error method and that's fine just remember that I already did that for you and the best method is the method I used on frame #2.

 

[Huron Angler]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Very impressed by the progress, and I'm glad that your numbers are adding up too

Looking forward to seeing her take shape as you forge ahead, nice work.

 

[sprintst]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Wow man. That's going to be one well built boat.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Thanks, I'm suprised you found the thread, I hate this new PHP BBS styling. I guess you can't complain too much when you use free software... You probably figured out if you just subscribe to a thread when you respond you can easily check back on it later. I miss the "My Replies" feature.

 

[Triton II]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Hi Steve. When you log on to iboats just click on Quick Links in the grey menu bar at the top of the page and then on Subscribed Threads in the pull down window. Effectively it's the same feature as My Replies was.

Great to see this terrific work... I visited the TABS factory who built my boat using 5mm plate and your construction method is similar. My thing, as SprintST called it "is built like a tank" and you'll have the satisfaction of having built your own tank soon enough. Can't wait to see more.

TII

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Thanks, TII I forgot to mention that in my original post. Another less permanent method is to use advanced search and search by user name. That returns a full set of posts that you've either started or replied to.

I finsihed the flange on Frame #6 last night. Funny, it was the least complex as far as bends but the most difficult because of it's location. I had to break out some 1-1/2" angle and make up some wedges so I had something to clamp too. Fortunately, after Frame #1 with it's multiple bends, (I'll post a pic when I get it final welded), I had plenty of practice at bending and I didn't need a lot of pressure to get the flat bar in tight.

That completes the fitting and tack welding of all the frame flanges. The flat bar bender is now out of the shop until I need it again much later in the build. There's that planning thing again.. I can't stress how important it is to think way ahead and often outside the box when you're building a boat this size in limited space. It will save you a ton of frustrations that would take all the fun out of the process.

I forgot to order curved edge flap disk's for grinding the fillet tack welds so I just did that. I'll be using a 4" Bosch diamond concrete blade mounted on my 4-1/2" grinder to do the back chipping which I'll also show in the next thread. Yes, this is a dangerous tool but as long as you respect it you can use it with a fair degree of safety. I may go get a pair of gloves with steel finger guards or just make some sort of a guard to protect my hands. You don't have to worry about it comming apart on you like a compostion wheel so from that aspect it's acutally a little safer. The key point is that the diamond blade won't contaminate the Al so the chance of unknowningly creating a bad weld is lessened.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Last night I finshed the full welding of Frame #6. The round edge flap discs made the job of grinding down the tack welds very easy. A lot of folks don't grind the tacks and instead just weld over them and smooth them out. I don't think that's a good way since tacks are sort of just a down and dirty way to make something hold temporarily. Suit yourself on that subject.

Here's the edge weld ground and ready to final sand and finish.

Here's the Fillet weld, this will remain as is.

Here's that Frame #1 I was talking about earlier. The cutout in the center is for the oil pan clearnce. That flange is all one piece of flat bar. I've pretty much decided to go outboard with this boat but just incase I change my mind anytime (even after it's finished) I could always convert to an inboard. I don't want to permanently exclude options.

Here's a little perspective of where we are right now. I'm working on the forward frames first so that I can put them behind me and then move my welding table and start working from the transom forward. It's the way I have to do it because of my limited space.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

This is the back chipping process. You back chip to remove any contaminated metal that may have accumulated when there are welds on the opposite side. Contamination occurs because there is no shielding on the back side of the weld. It's not entirely nececesary on this piece but I do it anyway.

Here's the initial grind -

Here it is after runing the curved flap disk over it -

And finally brushed and cleaned with Acetone -

I finished the edge weld last night. My TIG settings were 225 amps with 80/20 Ar/He mix and running fast pulse mode with peak pulse amps set to 185. These settings keep the weld from going over the edge on the 1/4" flange and concentrate it into the center of the joint for maximum penetration. I was running a 3/32 2% lanthanated tungsten with a #7 cup, gas lense and 25cfh of gas flow. Gas flow needs to be increased because the Helium floats the gas up and you need more CFH to keep enough on the weld.

 

[Huron Angler]

Re: Glen-L 21' Canyon Cruiser - Aluminum

She's really starting to take shape, looking good. I like the philosophy of keeping options on the table. If you need to convert to diesel down the road you will be all set

The corners on those structural pieces look like they give it lots of strength.

 

[Triton II]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Wow! That's about all I can say. Steve, this is like a master class in plate-alloy boat building and I'm thoroughly enjoying it. Thanks!

TII

 

[fat fanny]

Re: Glen-L 21' Canyon Cruiser - Aluminum

It's really hard to comment on any step of this project. It's like watching a very good documentary, very well thought out and informative and the welding is top notch.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Thanks everyone..

I laid down all the rest of the Fillet welds today so all 5 frames with flanges are just about done. That was 2'bs of 1/8" filler rod and about 70' of TIG weld. I still have 30' of edge weld left. If it's as cold tomorrow as it was today, welding will be my shop heater again..LOL works pretty good actually, I think I hit a high of 51 in the shop this afternoon.

I was tempted to grind down the fillet welds to make it pretty but then I remembered that nobody except maybe the recycler will ever see these welds. They'll be stronger if they're left as is.

I'm also weighing each piece now. This should give me an accurate weight and make it easy to locate the CB (center of balance). So far Frames 1-4 weigh in at 14lbs each. I won't bore you with the weight everytime I weigh something but I'll give some totals along the way so you can get an idea of where the weight is and how it's distributed.

 

[Luhrs28]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Those frames remind me of Boeing 747 construction. Once you have the outer "skin" and deck tieing it all together it's going to be amazingly strong.

I'm really enjoying the great write-ups and photos.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Those frames remind me of Boeing 747 construction. Once you have the outer "skin" and deck tieing it all together it's going to be amazingly strong.

I'm really enjoying the great write-ups and photos.

Actually, these frames float for the most part. The stress on a boat is longitudnal not transverse. Kind of amazing when you think about it. The bow takes most of the stress with Frame # 7 taking the worst beating. It doesn't float and is welded all around to the hull. I have it cut out but I haven't shown it yet. As the boat progresses you'll see what I mean.

You don't know how hard it is to keep my head and not weld the other frames in.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

I finished welding and grinding all the flanges on the frames last night. I dropped the transom down to the correct height and lined it up. The next step will be to true up the frames.

I think if I was going to do this again, I'd use 6061-T6 for the frames instead of 5052-H32. The 5xxx aluminums are hammer tempered off of a roll and the curve keeps comming back. On the otherhand it may just be the price I'm paying for heavily discounted metal. I'm going to work on some sort of truing jig tonight.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

First big mistake -

Apparently when I fitted up the flanges to the frames, my use of clamps and the direction I was clamping casued nearly 4" of shrink to occur at the top (sheer) of the frames. My attempts to correct it with hydraulic jacks only created more distortion in the frame. You can imagine the thoughts that went through my head as I invisioned discovering this after I'd plated the boat.

I was ready to succomb to buying 4 new sheets of 1/4 but stopped short after talking to my local supplier. 5052 is pretty forgiving so I cut the flange off Frame #4 with my festool saw. That was pretty easy. I followed that up by squaring up the edges with a flap disc on my 4-1/2" grinder. I don't think I lost more than 1/8" off the inside of the frame which isn't critical.

The next move was to try and square up the frame. I got myself 4 2x4x8' and clamped them up square to my bench top. I put a few reference marks on them and made a 1x4 x 7' spreader for the shear ends.

I started clamping at the centerline of the keel and worked as evenly as possible around and up to the sheer ends. By the time I got there I was only out 1/2" and was able to readjust the clamps and get it to fit into the spreader.

The next move was to make the flange out of three pieces instead of one. I started with the 30" center piece. I carefully fit it and tack welded it. I then added 2" stitch welds letting each weld cool before doing the next. I then did the same thing with the left side radius (one piece).

I had a couple of fights along the way with the width of my jig so I'm going to modify it today before I weld in the right side radius piece. I'll take pictures of it then and maybe someone reading this won't make the same mistake I did. It'll cost me about 100.00 in flat bar to correct it but it would have been well over a 1,000.00 if I had to remake them. That first 100' of TIG welding is also lost effort but time is on my side.

 

[sschefer]

Re: Glen-L 21' Canyon Cruiser - Aluminum

Here are a few pics of what's turning out to be a better way.

The form -

Better holding system -

Making the flange out of 3 pieces lets me be a little off with the bending. There's no way to keep the piece perfectly square in the bender and no way to straighten it after it's bent. That's what was causing the problems.

I figured out when I was putting the last radius piece in that if the piece is a little bit tweaked from the bending, you just have to let it go or try again. Mine weren't out enough to redo but I also didn't try to force the perfect fit. I just welded it together and ground off the visual imperfections.

I made back a little over 3" of width on the first one I did this way. I'm still shy by about 1/2" but that's acceptable and I can spread the frame with just my own strength.

I've got frame #3 cut and in the form now. Dang I hate doing things twice but if it aint right it aint right and that's just the way it is.