Can't find U-channel

[Rocky]

Hi guys, been trying local metal supply places, they don't get the U-channel in 4"x3"x.250 in 6061. Anybody with a source would be greatly appreciated. ( Capt Pat's engine bed caps process). Thanks, they DO have square tubing 4" x.250 I could table saw down to 3" throat but would rather just get AA channel.

[CaptPatrick]

Rocky,

The caps I made for Buddy Boy came from an odd lot at a distributor in WPB, Fl. and probably weren't a standard size. Since your caps will be epoxied down and lagged into the beds, I wouldn't worry too much about percise measurements. Here's an online source on your coast that might have something you could use: http://www.alcobrametals.com/display.php?id=511" onclick="window.open(this.href);return false;

[Bruce]

Don't know whether the 4" your referring to is inside or outside dimensions but on standard channel stock it would be 4" outside to outside with the interior being less the thickness of the two sides.

4x3 wasn't a standard size here only custom. I used mostly 4x2.

A cheaper alternative than a custom size is getting two 2x3 angles and having them welded down the seam, ground down and painted or powder coated. I've done that many times on odd ball stringer widths on larger boats that repowered.

Most welding shops or sheet metal shops can get the metal for you as suppliers are usually wholesale only.
Usually there is a minimum in length when ordering as in the last channel I ordered came in 20' lengths only. If you get a price make sure there isn't a minimum length and who your buying it from will part it out to you but in reality the price you pay will be for the whole length and they get the remainder all paid for by you.

[bob lico]

Rocky they sell 4" x 5" angle in 21' lengths . Buy this with one length of flat 4"stock and weld into U channel.you need. (4) 50" pcs. For a Bertram 31 so you will have a piece left over . you can use it for a tie between stringers where bulkhead sit on stringers holding engines.

[Rocky]

Capt Pat thanks for source, good I'm not feeling so bad I can't find exact stuff.
Bruce do you think the 4"x2" is sufficient for these caps? I was tempted to just cut down a 4" square tubing in .250" TH, I'd have it cut in no time with good blade as you know 6061 is very easy to.
Bob I see what your saying thanks, I was trying to avoid expense of welder since I lost my tig access.
Thanks for help guys.

[Bruce]

on my stringers that I built, I've never had issue with 4x2 caps bolted and expoxied down.
If you go the angle way use a mig welder. No need to tig it. Wire feeder will weld that seam in no time.

Check with some shops, you never know what they have. 4x3 maybe used more out there.

[Rocky]

Alright then, thanks Bruce I'll try some more places but sounds like 2" will do if 3" height of channel is unabtainable.
I have not sistered hardwood to stringers yet but wanted my channel first for measurement of total stringer/ sister thickness. BTW, do you still cut outboard stringer down approx 2" in rear no matter what engines are to be installed? I'm going Cummins but wondering if I should cut them down for access under engines when they are in, or other reasons to do so now?

[bob lico]

Rocky build a jig and you can see exactly how much to reduce the rear of stringers if nothing else take a 2" x 6" piece of wood and cut 11/2" hole ( shaft diameter) thru it at 24 degree dead rise and 14 degree shaft angle (coupound angle on drill press) put end of shaft into hold and cut wood at bottom same angle put on bilge floor dead center of your shaft log . This is your shaft jig and that will exactly match the output flange center to ZF Irm 220a gears. This is the height your engine gear will have to match. I would also build engine jig and get dead nuts first try.

[Rocky]

Hey Bob isn't there by now a welded up jig for the 6BTA flying around somewere? Corrisponding to ZF gear and front engine mounts? Or are there too many variables specific to boat/shaft angle and such?

[bob lico]

Other then my boat (changed shaft angle) all other 31 Bertram FBC would essentially used the same wooden engine jig. Brother Wayne whom is not to far from you installed his with wooden jig . The post above refers to a seperate jig for shaft to show you were the engine will sit on the stringers so you can cut rear of stringer and overlap with U channel the rest of the space will be done by ramps for the motor mounts to fit on. Side to side finish dimension must be 22" center of U Channel to center of U channel frot to back don' t matter just make channel go from main bulkhead to fuel tank bulkhead about 50" .

[Rocket]

Rocky, an alternative to getting channel or trying to weld aluminum angles together (aluminum welding being a specialized process that not everyone does well) you could get a fab shop with a decent size break press to fabricate the pieces that you require. I do alot of work with my fabricator and I know I could have custom piecces this afternoon if required. I am sure that you can find a local custom fab shop that would be able to create the exact sized caps out of .250" aluminum plate, or even stainless if that is the material that you would prefer to deal with. Another thing to bear in mind is the inside profile of extruded channel, it has a bigger radius than formed channel so you have to know the flat dimension to size your stringers.

[Rocky]

Rocket thanks I do know of a large fab / metal supply shop who can break the dimensions, but with a "we're proud of it price!" I can see online I can buy 4"x2"x.250" , cheapest route for this area for me right now. Thanks again Bob for dimensions on jig helps alot.

[Bob H.]

Rocky, had a local guy bend up stainless to make exactly what I needed. BH

[Rocky]

Bob that's quite the setup there, did you make a jig or use your engine/trans to find exact measurements? Didn't have to cut down outboard stringer looks like. What a clean look, you do awesome work.

[Craig G]

Check out Aluminum Distributing.

Aluminum Distributing, Inc. http://www.adimetal.com" onclick="window.open(this.href);return false; Fort Lauderdale, FL 33315 Phone: 954-523-6474, 866-825-9271 (toll free) Fax: 954-779-7355

[Bob H.]

Rocky, I started from the strut and worked forward with a laser aimed at the transmission. I didn't have to cut the stringer due to custom engine boxes that gave me extra clearance. The transmission was lined up first with no engine hell of a lot easier to wrestle around. I cut the ramps but only tacked them to the u channel, made the ramps from wood first until I got everything just right. Once you get the angle you just carry it forward to the engine mounts. I had a gantry made so I could hang the engine and work the ramps. BH

[Rocky]

Bob that technique with trans only first sounds like how Tony Athens does all his boat engine installs. Looks easier like you said to manipulate that iron around for initial setup. Can't wait till I have those baby's at my house, gonna be a while though but in the meantime doing preliminary things around them. BTW you have a following on the deck ledgers!

[Bob H.]

Rocky, Very nice work, that should last for another 50 years...dont forget the wire chases' on each side, make use of all your space to run wires and steering lines..BH

The tranny trick is from Tony Athens, give credit where credit is due..here are the plywood engine mounts I made up and brought to the fabricator..he was impressed..

The plywood jigs are over in Portugal with Luis..he asked for help so I packaged them up.

[Rocky]

Bob sorry for late response, been busy. Yes- I will definitely run the conduit as you did there ,and when I figure out what my exhaust is going to be I'll laminate those supports for pipe too.I like the mocked up mounts for metal fab shop- leaves no questions!
Craig I could not find from metal site there any u-channel minimum 2" throat so I might go the Bob H break to width/throat I need but thank you for info.

[CamB25]

Rocky - Nice work on the bulkheads and other strutures. Looks like you are using 5lb divinycell? Epoxy? Are you seeing any print through on the exterior hull sides from the tabbing? I am working on some similar structures for my 25...a bit concerned about print through when tabbing structures to the relatively thin hull sides.

thanks!
Cam

[Carl]

http://www.allmetalsinc.com/aluminum-angles.html" onclick="window.open(this.href);return false;

Rocky, they can cut to size and ship...pricey a far as material goes...but no minimum.


Heres two links to McMaster...they almost have it all...but make sure you have the Vasaline ready.
If you cannot buy direct, I can purchase and ship directly to you. You can pay the Captain.

http://www.mcmaster.com/#standard-alumi ... ls/=pgo9nh" onclick="window.open(this.href);return false;
http://www.mcmaster.com/#aluminum-angles/=pgoa6c" onclick="window.open(this.href);return false;


If you know what you want, I am sure I can get it for you at cost...but shipping is pricey and I will not be getting great pricing either as I'd have to pay cut charges or take drops. I deal with very little structural sizes..otherwise I'd offer what I have in stock. But I do buy a couple tons a month...so maybe an option.

If you are welding you want Grade 5086 (best corrosion resistance) or Grade 6061 with good corrosion resistance and usually best pricing as it is the most popular grade.

In my area there are a couple Scrap/Surplus Metal yards that buy a tremendous amount of material...From what I hear pricing can be good and they sometimes have oddball sizes that can be the ticket for your project. I have never been as I do not have time to rummage and I often require certification on material. Lots of Alum comes marked with grade and temper...so maybe look int that.

[Rocky]

Cam 25 - I just followed Capt's suggestion from my main forward bulkheads to just let the 1708 lay down in a natural curve on inside joints like that so can move and not have any hard spots, and mAking sure there is 1/2" of space between hull and supports on sides of hull.The bottom aft of engines bulkhead I filleted large fillets first before glassing in. As for material used- Coosa Baby! All the way..and of course epoxy for tabbing those secondary bonds. http://dan.pfeiffer.net/10m/bulkhead_tabbing.htm" onclick="window.open(this.href);return false; if your worried about print through I suppose you can treat your "tender" hull side like this illustration, but I'll bet the Capt would say unessessary to do so.

Carl- thanks very much for info and offer,I found my place here locally that will break /form my 6061 to my liking at a good price so now it's getting my hardwood pieces and following the Capt's instructions. It's a no hurry thing for me as I do not have the "iron" yet you know! I'll keep the pics coming though and you guys informed of progress. I really want to thank everyone here for there help- just awesome the people on this site..

[CamB25]

Thanks, Rocky. That 1/2" space seems to be the key...prevents that hard line (picket fence look) due to the concentration of adhesive. Onward!

[Bob Patton]

Rocky,
I assume your fabricator knows this but for general information you need to stress relieve 6061 at the bend line. It is most likely T6 and will crack on the outside of the radius if it is to be fairly tight, which I assume it should be to match the engine stringers. The easiest way to do this is to blacken the bend line with acetylene only of an oxy-acetylene torch and then make a neutral flame with both oxygen and acetylene and heat the bend line until the black disappears. This will anneal the bend area and it will possible to achieve a sharp 90 degree bend if necessary.

[Rocky]

Bob P the fab shop did say something about heat but did not go into detail about it, now that I know how it's done (thank you) I'll make sure he follows that procedure.