Removing Weld Induced Warping In Aluminum Panels

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ehsvp
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Removing Weld Induced Warping In Aluminum Panels

#1

Post by ehsvp »

Anyone have a good method of removing heat induced warping of aluminum panels from welding? I realize the best solution is to prevent it from the beginning with back stepping, braces, small size welds etc. I'm already past that point. The 1/8" aluminum flybridge on my boat has some distortion of the side panels which was caused by welding on some light brackets. Has anyone tried heat to straighten warped panels? How about cold mechanical methods. Thanks in advance for any good suggestions.

Bob
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gandrfab
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Re: Removing Weld Induced Warping In Aluminum Panels

#2

Post by gandrfab »

This is not my place and I don't recommend trying this on a fly bridge (show piece) for a first wack at it.
My limited experience that may have been that size has been with airboat hull sides.

The art of a hammer and dolly block. If I could put to words what I can see/feel I'd make a great writer.
Never hammer the high spot. It is sticking out and you want that spot to go back in with all your will but you can not hit that spot it will just stretch the metal further.
Make all your hits from the surrounding area and always have the block backing the impact.
Work it slow and eventually you will see metal moving the way you want, get frustrated, aggravated and mad and the metal will not cooperate. Walk away at those moments.

Large panels like airboats I have used a wood block about as big as I can hold in one hand and rubber mallet.
Smaller stuff metal blocks and various metal hammers.

Take a piece of 1/8" mock up a similar weld, clamp it to a fixed frame and practice.
If it holds your interest it become fun, entertaining and with persistence you will the find OMG I did that moments.
Think persuasion not frustration.

And pictures of he project would be great. Enjoy
kmorin
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Re: Removing Weld Induced Warping In Aluminum Panels

#3

Post by kmorin »

G&R, ehsvp, this topic is a bit wide scope to reply without pictures and some idea of the brackets' weld contractions?

I've worked on so many warped panels in so many ways that I've truly begun to forget the earliest instances! They were in the 70's when I started building and warped my own projects. Since then I've tried more than just a few methods but I did at least think I was applying a cure to some specific circumstance.

Your post is kind of open ended in regard posing a question, that seems to me, requires some actual facts in order to propose ideas for solutions. Pictures, as G&R has mentioned, would go a long way in helping anyone inclined to reply to have a basis for their ideas as applied to your warped panels.

Cheers,
Kevin Morin
Kenai, AK
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ehsvp
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Re: Removing Weld Induced Warping In Aluminum Panels

#4

Post by ehsvp »

Gentlemen, I've attached a picture of the problem area to this post. Thanks in advance for any help you can provide. The warping is most visible in the area of the light bracket. There is some bracing under the sheeting but it is minimal.
P1060538.JPG
P1060538.JPG (92.61 KiB) Viewed 16223 times
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gandrfab
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Re: Removing Weld Induced Warping In Aluminum Panels

#5

Post by gandrfab »

I wouldn't jump right to hammering on it 1st.
kmorin
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Re: Removing Weld Induced Warping In Aluminum Panels

#6

Post by kmorin »

ehsvp,
not exact on my understanding of the warping because like most aluminum photography- shades of gray! It appears the hand rail has created a pair of cups- inward toward the keel? both welds don't appear to have remained flat- or the area surrounding them don't?

Next the light mount base appears to have created a contraction around its continuous welds and there seems - based on my view of the shadow beginning below the hand rail, running through the rail's span and upward to the right in this photo- a ridge or outward bow?

So I'll tell you what I'd do personally.
First I'd cut off the bracket and the hand rail.
Then I'd remove all the framing inside the dodger/bridge shroud.
Then I'd sand the entire sheet fair outside, while it is wrinkled; using 3M ScotchBritetm or equivalent.
Then and this is key to my opinion of how to smooth this panel; I would create internal frames that were bowed from the forward (aft raked) edge to the stern edge of the dodger side. In this curve I would make the forward corner 'hard' or fitted to the dodger- regardless if it were a smaller rolled inside corner or a sheet edge (can't tell in image) and the fit under the flat bar (assumed liner to the dodger's side top edge) so the piece would hold a curve outward once tacked inside the dodger side.

I'd build three min. four would be better of these horizontal bars/longitudinal frames and plan their length to tack them where the light fixture will be mounted, and at least where the hand rail will be replaced.

NOTE: these pieces must (MUST) stretch the side sheet/plate/panel outward at least 1/2" to 5/8" or.... I don't think there will be enough 'stretch' to recover the side panel's fairness. I am not recommending trying to make a flat panel- I'm saying that I would ONLY attempt to make the panel into a cylindrical section (slightly compound convex curvature) in order to
A) recover the former contractions,
B) add an over-riding pressure outward to make the sheet stretch to a smooth surface
C) supporting the sheet in a new (bulged) shape so that it can withstand the welds of the replaced fittings on the outside.

Further steps I would take. Before putting the three or four longs in; I'd temporarily push the panel outward using cripples from the house top or other side- jammed into the dodger for spreading power- and then tack an oversized doubler plate where the outside welds will go. I would personally use a 2-3x size expansion where a 4" fitting for the light would have an 8" fitting inside the dodger highly rounded corners of a rectangle and circles for the hand rail.

I would notch the curved longs (they'd have to be sawn to a curve, and likely 1/4" bar?) so they lay fair to the inside surface of the bulged sides and to the surface of any doublers. I would only stitch the doublers on using a 5-8 dime weld, spread around the surface, and not continuously welded. The doublers stitch welded on will help to minimize the outside welds' contraction on the now bulged outward dodger side.

When I put the light fitting/base on; I would bevel the outer edges 45-50 degrees so the weld was recessed into the material of the base's sides and i would use a small TIG weld to do that work. If you don't have TIG then I'd rig four (number of sides??) separate welds- I'd arrange run on/run off blocks at the beginning and end of each weld so I could use a machine or drag type weld (term from stick and steel MIG- not proposing to drag aluminum MIG)

This would result in very small cross section welds- done very fast at high WFS and wattage. Combined with the beveled sides to recess the weld and the fast drag- down hand is fine- the weld face will be very narrow and will not be enough to
1) pull up the surround plate off the doubler behind the welds &
2) because of the longitudinal stiffener now inside the dodger- the continuous weld will not be enough to contract the entire panel.

Regarding the replacement of the hand rail- I'd follow the same basic procedure- bevel the pipe ends after flatting to a fit. Backing up each end with a round 2x-3x the size of the pipe end of plate just thicker than the dodger sides; making sure to stitch ONLY the inside doubler so that it does not contract and bulge the dodger side when those welds cool. typicall these small round doublers would have 3 or 4 welds holding them on - and they'd only be 3 dime welds to avoid creating heat distortion.

Welding out the pipe ends is a pain with MIG or TIG because of the pipe being in the way of the inside welds. Again, using top and bottom run on/run off blocks, I'd weld from 12:00 down to 6:00 both clockwise and counter clockwise keeping the bead as small inside the recess of the beveled pipe end as I was able- and going as fast as I could to keep the deposited wire minimal- the face/width of the resulting welds is the biggest contribution to the contraction of the sides in the first place.

Putting in proportional welds on these types of fittings/brackets/fixtures is a "change in gear" from hull welding or structural framing welds. The former are picky and need to be very fast to be small to avoid contraction more than the latter which are a little more forgiving but will still make a hull 'hungry sided' or show the ribs if done out of proportion to the materials- while not increasing any structural integrity of the hull.

So, while a bit long in reply, you asked what others would do ? and that is how I'd go about cleaning up the wrinkles in this flying bridge dodger. I do not believe it can be flattened, smoothed or faired any other way? I cannot see hammering a sheet flat that has large weld contractions in the field on one side??

Cheers,
Kevin Morin
Kenai, AK
kmorin
ehsvp
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Re: Removing Weld Induced Warping In Aluminum Panels

#7

Post by ehsvp »

Kevin thanks for the response. I understand what you are suggesting I try to achieve, a very minimal amount of welding on the side, once the panel is supported with reinforcements inside.

Bob
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gandrfab
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Re: Removing Weld Induced Warping In Aluminum Panels

#8

Post by gandrfab »

Not knocking Kevin at all. I admire all the wisdom he has shared and may share in the future.

In many situations customers can or will not pay for a lengthy process to have a job done correctly.
I have seen this and been low or out of work at the time on various jobs leaving a customer and I in a position to make ends meet.
Customer gets something that will work and I have a job to do.

Without hands on I wouldn't even want to attempt a way to concoct a solution for this issue.
Leaving me to ask are there other ways to skin this cat? Say for someone with tighter budget.
kmorin
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Re: Removing Weld Induced Warping In Aluminum Panels

#9

Post by kmorin »

G&R, I do understand the work I've outlined is not going to be a 2 hour job. And as I've done countless times when replying to online questions of "How can I do this?" I spend others' money freely!

But in this case the "damage is already done" so... if the question is how to smooth a wrinkled/warped surface? That's what it will take to flatten/smooth this surface- it will have to be stretched outward, braced, faired and the attachments redone (correctly).

Cheap? Low cost? Inexpensive? not really, that door closed when the work/design wasn't done right the first time.

I regularly say to apprentices and helpers that doing the job right the first time is the least expensive: if you don't (#1) then you have to take it apart (#2) and finally do it right (#3). I think its at least 3 X as expensive to "short cut" quality work? My list of 'how too's' provided here is mainly based on the times I didn't take care the first time!!!

You know why I did the work wrong? " I was saving money "

Cheers,
Kevin Morin
Kenai, AK
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gandrfab
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Re: Removing Weld Induced Warping In Aluminum Panels

#10

Post by gandrfab »

As always very well put.
And it would be great if every customer could understand that.
It would be even better if I was busy only doing work that I want to do the right way.

Sure I could turn my nose up and say I'm going to do it right or not at all.
But then the commercial fishing boat that has to work tomorrow or the week end warrior that only has this weekend to fish won't be able to. Or they find someone else to make the fix.
So many time's I have given the customer enough to get the job done, they are happy, tell all their friends about me and I get a pay check.
Part of my life's vicious circle.
kmorin
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Re: Removing Weld Induced Warping In Aluminum Panels

#11

Post by kmorin »

gandrfab wrote: Tue Mar 12, 2019 5:39 am Sure I could turn my nose up and say I'm going to do it right or not at all.
G&R, you can view the refusal to do a poor job as "turn(ing) my nose up" OR you can say that you're setting a standard for your shop?

I used to be in full agreement with your terminology- I wouldn't refuse any job- no matter if i knew it was not a quality method. After listening to the Skipper, I'd show him my ideas, he'd show me his, we'd talk costs, time materials and I'd usually - verbally only- say "Well I'll do it your way but I don't think that's a good design or method of work... and it may turn out to be (weak? inadequate? rough looking? etc.) less than a good job."

Then I'd do the work, exactly as the Skipper wanted, and it would turn out poorly, cheaply done is often a poor job, and what would happen?

The Skipper of one skiff came back and claimed I had to "make good" on cracks in an inadequate structure he'd designed. He proposed I fix for free what he'd said was the only way for me to "get the work". But I'd taken the precaution of having him copy his sketch and initial it... then write my work order and it was signed and dated- and when he went to his lawyer because I was a rat and low life... he was told he could be sued for fraud if he attempted to go ahead with his BS law suit.

What this taught me was there is a part of the market in welded boats- that I can't afford to work for. They may look like a pay day- but in fact they were a long term problem disguised as a client! Quite frankly not everyone can afford many aspects of life's different tools and vehicles. Welded boats aren't cheap and that's why there's a riveted boat market... not everyone is in a position to afford the best. But that doesn't mean I'm obligated to afford their economic status.

I definitely agree that commercial fishermen are on a budget, but if they can pay for gear, fuel and the boat; they can afford my work- or.... if my work isn't worth it? find someone else. No nose up: just my standards of work.

G&R you're welcome to your ideas about "turning up my nose" at poorly designed work, and I'll stick with my countless numbers of instances where that is the only way to remain in long term quality building services. While pretty much retired, I still have a decent rep for doing good work, and building boats; right. I did "turn the corner" when I quit being the low cost 'slop shop' in the neighborhood and passed that on to others. A couple of them figured it out as well, years later, but some remain and their rep.s here, aren't what I'd want?

We've totally high-jacked the thread with our discussion of service work design and implementation standards, but I hope its worth the read to the Forum?

Cheers,
Kevin Morin
Kenai, AK
kmorin
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