I need to make a couple boat trailers... Of course I can pie slice and
weld, but I'd prefer to bend. Professional trailer members are bent
(well except the really small stuff or the really big stuff). Setting
up a hydraulic system with bending dies is an option, but its a more
than a few cents and a fair bit of work for what will likely be a dozen
bends ever.

I need to make two types of bends. Inwards towards the hollow of the C,
and downwards from flange to flange.

Tube is actually much easier to bend than C channel, but tube frame
trailers tend to rust out from the inside. You don't even know how bad
it is until you are at the failure point. C channel frame trailers rust
very slowly if at all because all the water runs right off.

I've got a small/medium OA torch, 20 ton jack style press, and a little
bit of machining equipment.

--
Bob La Londe
CNC Molds N Stuff

--
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On 03/10/2023 00:43, Bob La Londe wrote:
> I need to make a couple boat trailers...  Of course I can pie slice
> and weld, but I'd prefer to bend.  Professional trailer members are
> bent (well except the really small stuff or the really big stuff). 
> Setting up a hydraulic system with bending dies is an option, but its
> a more than a few cents and a fair bit of work for what will likely be
> a dozen bends ever.
>
> I need to make two types of bends.  Inwards towards the hollow of the
> C, and downwards from flange to flange.
>
> Tube is actually much easier to bend than C channel, but tube frame
> trailers tend to rust out from the inside.  You don't even know how
> bad it is until you are at the failure point.  C channel frame
> trailers rust very slowly if at all because all the water runs right off.
>
> I've got a small/medium OA torch, 20 ton jack style press, and a
> little bit of machining equipment.
>
Knowing what size material you're trying to bend would be helpful. I've
bent smaller 1/2" x 1/2" x 1/16" in a home made rotary draw bender and
got really good results on either axis but I did use a sacrificial close
fitting filler piece to support it during bending.

On 10/2/2023 5:08 PM, David Billington wrote:
> On 03/10/2023 00:43, Bob La Londe wrote:
>> I need to make a couple boat trailers...  Of course I can pie slice
>> and weld, but I'd prefer to bend.  Professional trailer members are
>> bent (well except the really small stuff or the really big stuff).
>> Setting up a hydraulic system with bending dies is an option, but its
>> a more than a few cents and a fair bit of work for what will likely be
>> a dozen bends ever.
>>
>> I need to make two types of bends.  Inwards towards the hollow of the
>> C, and downwards from flange to flange.
>>
>> Tube is actually much easier to bend than C channel, but tube frame
>> trailers tend to rust out from the inside.  You don't even know how
>> bad it is until you are at the failure point.  C channel frame
>> trailers rust very slowly if at all because all the water runs right off.
>>
>> I've got a small/medium OA torch, 20 ton jack style press, and a
>> little bit of machining equipment.
>>
> Knowing what size material you're trying to bend would be helpful. I've
> bent smaller 1/2" x 1/2" x 1/16" in a home made rotary draw bender and
> got really good results on either axis but I did use a sacrificial close
> fitting filler piece to support it during bending.
>

We are talking trailers here so 3" and/or 4" steel channel. For small
stuff like you are talking about I might just make some single use dies
out of scrap aluminum. I have a lot of it.
--
Bob La Londe
CNC Molds N Stuff

--
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On 03/10/2023 01:22, Bob La Londe wrote:
> On 10/2/2023 5:08 PM, David Billington wrote:
>> On 03/10/2023 00:43, Bob La Londe wrote:
>>> I need to make a couple boat trailers...  Of course I can pie slice
>>> and weld, but I'd prefer to bend.  Professional trailer members are
>>> bent (well except the really small stuff or the really big stuff).
>>> Setting up a hydraulic system with bending dies is an option, but
>>> its a more than a few cents and a fair bit of work for what will
>>> likely be a dozen bends ever.
>>>
>>> I need to make two types of bends.  Inwards towards the hollow of
>>> the C, and downwards from flange to flange.
>>>
>>> Tube is actually much easier to bend than C channel, but tube frame
>>> trailers tend to rust out from the inside.  You don't even know how
>>> bad it is until you are at the failure point.  C channel frame
>>> trailers rust very slowly if at all because all the water runs right
>>> off.
>>>
>>> I've got a small/medium OA torch, 20 ton jack style press, and a
>>> little bit of machining equipment.
>>>
>> Knowing what size material you're trying to bend would be helpful.
>> I've bent smaller 1/2" x 1/2" x 1/16" in a home made rotary draw
>> bender and got really good results on either axis but I did use a
>> sacrificial close fitting filler piece to support it during bending.
>>
>
>
> We are talking trailers here so 3" and/or 4" steel channel.  For small
> stuff like you are talking about I might just make some single use
> dies out of scrap aluminum.  I have a lot of it.

OK you're building a trailer and I saw boat and assumed it was the Al
boat you're working on, my bad. Still with a 20 ton press I would expect
the first bending requirement to be doable given you can get supports
and constraints into your press similar to a hydraulic pipe bender,
bending that section depth wise is likely to be another matter. What
about fabricating from box section and galvanising it if you're worried
about rust. Galvanising is a cheap bulk process if you have a galvaniser
locally and IIRC in non salt environment can be good for 70 years and
more, less in salt environment but still a good time.

On 10/2/2023 6:19 PM, David Billington wrote:
> On 03/10/2023 01:22, Bob La Londe wrote:
>> On 10/2/2023 5:08 PM, David Billington wrote:
>>> On 03/10/2023 00:43, Bob La Londe wrote:
>>>> I need to make a couple boat trailers...  Of course I can pie slice
>>>> and weld, but I'd prefer to bend.  Professional trailer members are
>>>> bent (well except the really small stuff or the really big stuff).
>>>> Setting up a hydraulic system with bending dies is an option, but
>>>> its a more than a few cents and a fair bit of work for what will
>>>> likely be a dozen bends ever.
>>>>
>>>> I need to make two types of bends.  Inwards towards the hollow of
>>>> the C, and downwards from flange to flange.
>>>>
>>>> Tube is actually much easier to bend than C channel, but tube frame
>>>> trailers tend to rust out from the inside.  You don't even know how
>>>> bad it is until you are at the failure point.  C channel frame
>>>> trailers rust very slowly if at all because all the water runs right
>>>> off.
>>>>
>>>> I've got a small/medium OA torch, 20 ton jack style press, and a
>>>> little bit of machining equipment.
>>>>
>>> Knowing what size material you're trying to bend would be helpful.
>>> I've bent smaller 1/2" x 1/2" x 1/16" in a home made rotary draw
>>> bender and got really good results on either axis but I did use a
>>> sacrificial close fitting filler piece to support it during bending.
>>>
>>
>>
>> We are talking trailers here so 3" and/or 4" steel channel.  For small
>> stuff like you are talking about I might just make some single use
>> dies out of scrap aluminum.  I have a lot of it.
>
> OK you're building a trailer and I saw boat and assumed it was the Al
> boat you're working on, my bad. Still with a 20 ton press I would expect
> the first bending requirement to be doable given you can get supports
> and constraints into your press similar to a hydraulic pipe bender,
> bending that section depth wise is likely to be another matter. What
> about fabricating from box section and galvanising it if you're worried
> about rust. Galvanising is a cheap bulk process if you have a galvaniser
> locally and IIRC in non salt environment can be good for 70 years and
> more, less in salt environment but still a good time.
>

From what I have seen no matter what you do moisture gets inside tube
frames, and it rusts out from the inside. I've repaired a few
commercially built tube frame trailers and seen many more with the same
problem.

The boat I am working on right now is likely around 1000lbs with
outboard. A little more with fuel, and rigging. It has a rusted out
factory tube frame trailer. I welded scabs on it to keep the cross
members from breaking many year ago for the previous owner. In return he
colluded with my wife to give me my first auto dark welding helmet for
my birthday. Thank you Gary. That made a world of difference in my
welding over the years.

My last glass boat was closer to 3500 and came on a 4" C-channel frame
trailer.

All fresh water for me, but I've seen what happens to trailers used in
salt. Its not pretty.

I would prefer not to pie cut and weld, but if I have to I have to. I
DO NOT want to use tube.

--
Bob La Londe
CNC Molds N Stuff

--
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"Bob La Londe" wrote in message news:uffmrl$36lma$1@dont-email.me...

>>
>> I need to make two types of bends. Inwards towards the hollow of the C,
>> and downwards from flange to flange.
>>
We are talking trailers here so 3" and/or 4" steel channel. For small
stuff like you are talking about I might just make some single use dies
out of scrap aluminum. I have a lot of it.
Bob La Londe

----------------------------

If you can fit it between the press uprights the long way bending it toward
the opening should be fairly simple, but bending from flange to flange has
the problem that it's not symmetrical and will try to twist. I straightened
8' lengths of 3" and 4" channel in both directions with much less than 20
tons.

I'd notch and stick weld, or for a road vehicle have a pro do it. Much of my
sawmill is welded 3" channel.

Today I made car underbody rust repair parts from 22 gauge galvanized. The
curved corners were bent on a 3-in-1 brake by reversing the dies square top
edge down and pressing the sheet metal to the intended radius with a round
rod under the dies.

This is what I used for the properties of C channel.
https://www.engineeringtoolbox.com/american-standard-steel-channels-d_1321.html

The pieces of C3x4.1 and C4x5.4 I bought tended to measure less than the
table gives. Their calculated values for Ix and Iy weren't different enough
to change the design, as I needed to use what I had. The low values of Iy
reflect a tendency to twist at a loading that Ix indicates should be
acceptable.

On Mon, 2 Oct 2023 16:43:38 -0700, Bob La Londe <none@none.com99>
wrote:

>I need to make a couple boat trailers... Of course I can pie slice and
>weld, but I'd prefer to bend. Professional trailer members are bent
>(well except the really small stuff or the really big stuff). Setting
>up a hydraulic system with bending dies is an option, but its a more
>than a few cents and a fair bit of work for what will likely be a dozen
>bends ever.
>
>I need to make two types of bends. Inwards towards the hollow of the C,
>and downwards from flange to flange.
>
>Tube is actually much easier to bend than C channel, but tube frame
>trailers tend to rust out from the inside. You don't even know how bad
>it is until you are at the failure point. C channel frame trailers rust
>very slowly if at all because all the water runs right off.

If you can weld here, you should also be allowed to heat to red in a
coal forge and then bend.

Joe Gwinn

On Mon, 2 Oct 2023 16:43:38 -0700, Bob La Londe <none@none.com99>
wrote:

>I need to make a couple boat trailers... Of course I can pie slice and
>weld, but I'd prefer to bend. Professional trailer members are bent
>(well except the really small stuff or the really big stuff). Setting
>up a hydraulic system with bending dies is an option, but its a more
>than a few cents and a fair bit of work for what will likely be a dozen
>bends ever.
>
>I need to make two types of bends. Inwards towards the hollow of the C,
>and downwards from flange to flange.
>
>Tube is actually much easier to bend than C channel, but tube frame
>trailers tend to rust out from the inside. You don't even know how bad
>it is until you are at the failure point. C channel frame trailers rust
>very slowly if at all because all the water runs right off.
>
>I've got a small/medium OA torch, 20 ton jack style press, and a little
>bit of machining equipment.
>
>--
>Bob La Londe
>CNC Molds N Stuff
I'd be fabbing, not bending, Cut the flanges off the channel where
you need to bend and cut plate to the required curve and weld it on.
Grind the joints, prime and paint. A WHOLE LOT easier than stretching
and shrinking the flanges to make a bend

On Mon, 2 Oct 2023 18:35:54 -0700, Bob La Londe <none@none.com99>
wrote:

>On 10/2/2023 6:19 PM, David Billington wrote:
>> On 03/10/2023 01:22, Bob La Londe wrote:
>>> On 10/2/2023 5:08 PM, David Billington wrote:
>>>> On 03/10/2023 00:43, Bob La Londe wrote:
>>>>> I need to make a couple boat trailers...  Of course I can pie slice
>>>>> and weld, but I'd prefer to bend.  Professional trailer members are
>>>>> bent (well except the really small stuff or the really big stuff).
>>>>> Setting up a hydraulic system with bending dies is an option, but
>>>>> its a more than a few cents and a fair bit of work for what will
>>>>> likely be a dozen bends ever.
>>>>>
>>>>> I need to make two types of bends.  Inwards towards the hollow of
>>>>> the C, and downwards from flange to flange.
>>>>>
>>>>> Tube is actually much easier to bend than C channel, but tube frame
>>>>> trailers tend to rust out from the inside.  You don't even know how
>>>>> bad it is until you are at the failure point.  C channel frame
>>>>> trailers rust very slowly if at all because all the water runs right
>>>>> off.
>>>>>
>>>>> I've got a small/medium OA torch, 20 ton jack style press, and a
>>>>> little bit of machining equipment.
>>>>>
>>>> Knowing what size material you're trying to bend would be helpful.
>>>> I've bent smaller 1/2" x 1/2" x 1/16" in a home made rotary draw
>>>> bender and got really good results on either axis but I did use a
>>>> sacrificial close fitting filler piece to support it during bending.
>>>>
>>>
>>>
>>> We are talking trailers here so 3" and/or 4" steel channel.  For small
>>> stuff like you are talking about I might just make some single use
>>> dies out of scrap aluminum.  I have a lot of it.
>>
>> OK you're building a trailer and I saw boat and assumed it was the Al
>> boat you're working on, my bad. Still with a 20 ton press I would expect
>> the first bending requirement to be doable given you can get supports
>> and constraints into your press similar to a hydraulic pipe bender,
>> bending that section depth wise is likely to be another matter. What
>> about fabricating from box section and galvanising it if you're worried
>> about rust. Galvanising is a cheap bulk process if you have a galvaniser
>> locally and IIRC in non salt environment can be good for 70 years and
>> more, less in salt environment but still a good time.
>>
>
> From what I have seen no matter what you do moisture gets inside tube
>frames, and it rusts out from the inside. I've repaired a few
>commercially built tube frame trailers and seen many more with the same
>problem.
>
>The boat I am working on right now is likely around 1000lbs with
>outboard. A little more with fuel, and rigging. It has a rusted out
>factory tube frame trailer. I welded scabs on it to keep the cross
>members from breaking many year ago for the previous owner. In return he
>colluded with my wife to give me my first auto dark welding helmet for
>my birthday. Thank you Gary. That made a world of difference in my
>welding over the years.
>
>My last glass boat was closer to 3500 and came on a 4" C-channel frame
>trailer.
>
>All fresh water for me, but I've seen what happens to trailers used in
>salt. Its not pretty.
>
>I would prefer not to pie cut and weld, but if I have to I have to. I
>DO NOT want to use tube.
>
>--
>Bob La Londe
>CNC Molds N Stuff
The only way to use tube for a boat trailer is to hot dip galvanize
it and make sure all the tubes are "connected" with adequate size
holes to let the zinc circulate throughout. Iven a channel steel
trailer I would want to galvanize - even for fresh water.