Spitfire 1500 - Re-Living My Youth (RLMY)

[Pettifordo]

14 hours ago, Mathew said:

Best way with flow is to listen to it and feel it.

@Matthew could you explain that a bit more - what kind of sound an I listening for ? I can hear it coming out at either 6 or 12 🤣🤣

[Pettifordo]

11 hours ago, chrishawley said:

Onwards and upwards! It comes with patience and rehearsal. If I get a chance later this week I see if I can find some photos to illustrate some of my suggestions above.

Thanks for taking the time to explain things so clearly - I will keep practicing - might be OK by the time I finish 🤣🤣🤣

[Pettifordo]

1 hour ago, Colin Lindsay said:

I've been reading this site recently... but can't do anything without an actual welder...

I might have one going second hand if I don’t improve soon 🤣🤣🤣🤣

Today I’m going to try to get the tub on the rollover jig (have braced it).

This will be my next post and a change from horrible welds 🧐🧐

[Josef]

I found this video very useful. The welder the guy is using is an extremely fancy one with way more adjustment than any hobby machine, but it does show you how to recognise which adjustment you need to make by the appearance / sound of your weld. (Though generally I don’t run beads on car panels, rather build up the seam from many overlapping tacks - there’s probably a proper name for this but I don’t know it…)

[Pettifordo]

So a productive day getting the car on the rollover jig.

Took about 2 hours to assemble and get the mounts on the car, then another hours and 3 friends to get the car on the jig.

The result is great, sooo much easier to work on the car and it stores away better AND I can get it into good light for welding 👍👍👍

I wasn’t going to get one but I met at chap called Mark at the Xmas Club meeting and he convinced me it was worth it - I have to agree.

I purchased from Ade - https://www.facebook.com/groups/282852072088530/?ref=share

[chrishawley]

As promised here's a few illustrative photos'. But with a strong caveat opinions vary about optimal techniques for different circumstances.

Specimen #1: upper weld made with impaired vision. Evident wander. Lower weld made wit exactly same machine settings but with clear sight and the shroud firmly held and close up (nearly touching) the work. Acceptable 'caldera' like appearance.

Speciemn #1R: Is the reverse side of #1 showing minimal if any penetration of the 'bad' weld. The good weld shows full penetration (= good)

 

Specimen #2: Much the same result as #1 but this time a weak single handed grip on the torch. You can see where the electrode has struck and bounced off  and then restruck a few mm to the left.

 

Specimen #3: Show 9 single pulses of weld (top and bottom rows) and then what it's like (middle) if one makes the pulses contiguous. That's now a continuous weld without any pinholes or burnback.

 

Specimen #3R: Is the reverse and illustrates full penetration weld and continuous on the reverse (ok, pehaps a little over penetrated but it is 0.8 steel).

 

Specimen #4: Is an actual join along a 1mm gap. Acceptable calderas each one merging into the foot of the next.

Getting the pulses to be contiguous is really hard to describe, but roughly: Lay in the first pulse. The operator then has 2 - 3 seconds while the initial weld is still glowing bright red to plant ( by sight) the electrode  tip in foot of the first caldera and make the second strike, then 2 -3 seconds again and so forth. But as heat builds up in the material the duration of the each pulse has to be diminished as the line of welds develops.

I'm not sure I've explained any of this very well so do post back if I've been obscure.

 

[KevinR]

1 hour ago, chrishawley said:

As promised here's a few illustrative photos'. But with a strong caveat opinions vary about optimal techniques for different circumstances.

 

Chris,  Many thanks for the illustrations, they should be a great help to those that are a little nervous about their welding.

Most of my MIG welding is on much thicker sections - usually between 3mm and 8mm thick steel, but in general the results I get are similar to yours, except I get much less penetration as the metal is so much thicker and I can only go up to 150 Amps.

My next challenge is TIG, just waiting for a Jasic 200P AC/DC Mini Digital to arrive so I can start teaching myself TIG welding - how hard can it be ? (I learned to gas weld about 45 years ago, and the last time I used gas for welding was 35 years ago)  There are some very good videos on Youtube, and it doesn't look too difficult.  Once I've mastered steel, I'll move on to aluminium and give that a go.  

Anyone give TIG welding lessons near Cambridge.

[Pettifordo]

21 hours ago, chrishawley said:

I'm not sure I've explained any of this very well so do post back if I've been obscure

@chrishawley thank you for taking the time to post these examples - I am definitely guilt of having a go one handed and/or rushing to weld instead of taking my time - I have now learned that undoing a crap job is much harder than just doing it right in the first place.

I’m planning my next weld (number 5) on the offside rear wheel arch - things I’m going to do differently to the other side (see horror show of pigeon s**t above)

1) rub down both sides gently to get the paint off but not loose any thickness on the metal

2) Cut the rust out with a good inch extra to make sure all the rot is out and metal is a thick as possible

3) Attach a plate behind the hole with 0.5 inch overlap

4) Use self tapping screws to get the two surfaces as close to each other as possible

5) Do a series of spot welds which I will join up as per example 4 above

As I mentally picture it, it looks perfect !! Saturday will see what really happens 🤣🤣🤣🤣

 

 

[Bfg]

Might I suggest ..

1) a flapper wheel or power-wire-brush will clean the surface and yet take next-to-no thickness off the steel.

2) cut out the worst of the rust yes, but why an extra inch ? that just means a larger patch to shape accurately, and considerably more welding. for example a 1-1/2" (38mm) dia hole or patch has a 119mm circumference, whereas as a 1" larger dia hole or patch has 279mm circumference.  That's 11" of welding. And the more you weld the more chance there is of distortion, and more refinishing to do. 

3) agreed, but practice shaping that plate as a compound curve.. Preparation  in making the patch fit really well will make welding it flush to the surface very much easier and then save a whole lot of time in refinishing. It'll look much better when done too.

Panel beating ; All that takes is hammer and a block of timber.  Hammer the middle of your metal patch when it is resting flat on a block of timber (I'm using a 4 x 2" or a 3 x3" block sitting on the end of my B&D workmate) and then work around that as a spiral. Start again in the middle and around again as a spiral and you'll find that the metal in the middle stretches to make your patch slightly domed shape.  The hammering doesn't have to be that hard as to massively dent it, that of course depends on plate thickness, but in general it just needs to dint it down a 0.5mm at a time.  If you have a piece of thick copper sheet then it's very much easier to work and practice with.  For shallow dishes no heat (no blowtorch is necessary). Turn the patch around to fit the hole in the body, and mark (with a felt pen) it's orientation so that when you weld it - it's already a great fit with it's edges sitting down flush.  

4) I very rarely use self tappers ..and then only when panels are overlapping (like making an access cover) and then those self-tapped holes will remain part of the finish article.  That's just more work.. to drill, screw / tap, to remove that screw, and then re-weld and refinish it.  I use an offcut strip or rod of steel, or an old screwdriver, to hold the patch in place for the first tack. And then the same to hold the other side of the plate down flush for the next tack ..and so on until there are tack welds all the way around.

Most important things are

• preparation - clean the metals to be welded, and accurately shape the pieces. De-burr those edges otherwise the parts will not sit flat.  BTW under-seal and wax-oil will ignite, paint melts and burns with toxic fumes and like zinc will cause your weld to splatter ..so everything is best cleaned off anyway. 
• welder set-up.  Start on a practice piece (of the same thickness) which is easy to hold and stand over, rather than getting straight in to working with a contorted posture. 
• good Earth to the metal your welding.  Inevitably, that too will necessitate thoroughly cleaning the paint and crud off where your earth clamp will be.
• good posture and visibility - working in a dark corner usually means that you'll miss the spot your aiming to weld, and an awkward posture will make it difficult to hold your hand steady.  Getting yourself in a good working position makes all the difference to doing a good job.
• protect yourself and the surroundings (especially glass, trim, paintwork, chrome, soft metals, nearby wires and plastic parts.. and of course the petrol tank, filler and its pipes) - It's difficult to focus when splatters come back and land on your scalp ..&/or you're worried that the car might explode or otherwise be damaged.  The surroundings also include your working space / garage, any paint, parts cleaner or fuel containers, other vehicles, blocks of wood, clothes or bundles of rags. Rags, wipes, tissues, etc. should not be in the bottom of the car.  Never weld a car with its battery, ECU or alternator connected.  Welding sheets / fire blankets are cheaply available from your local hardware supplier, or off e-bay, amazon, etc.  Cardboard &/or other dust sheets are not suitable.    Young children &/or pets should not be in the work space. Anyone else should be warned when you're welding. 
• if any weld doesn't work..  STOP and THINK  "why is that so crappy ?"  If necessary clean that up and start again.  ie., Don't compound splatter or a blow-hole with more of the same.  Grinding and linishing are filthy, noisy, damaging, and potentially dangerous activities and so are best avoided ..by welding neatly in the first place.   
• To "quickly / just do that" usually leads to something going wrong. ie., the weld being shyte, blowing a hole through, or a stray spark damaging something nearby.
• After you finished welding, keep an eye on that working environment for an hour.   Many a garage / workshop have burnt down because a stray spark has landed in corner and only quietly smouldered away ..until after the man has gone home.  Have a fire blanket and a decent capacity (in date) extinguisher close to hand.  
• Most of the same applies to grinding. Those sparks are literally WHITE HOT and can fly and bounce off things and into dusty corners.  Glass, trim, and paint is very easily damaged and so on...   

Schoolboy error # 1.  is to weld or grind near a windscreen, the back or side windows ..without protecting them first.  It's just dumb to end up with little black bits burnt onto the inside of a windscreen.  Schoolboy error # 2. is to take the glass or doors off and to put them next to the car your welding and grinding.!   Schoolboy error # 3. is to wind the windows down and forget there's no trim pad, nor anything else, to prevent splatter from burning into the glass.!   Old codger error # 1. is to pay someone else to do these things

I'm sure others would be able to make worthwhile contributions to these notes..

Anyway, I hope they help.  Welding is actually very satisfying because it's creative. Welding beautifully is especially so - That's craftsmanship.     

Pete

[Pettifordo]

On 06/01/2022 at 11:57, Bfg said:

Welding beautifully is especially so - That's craftsmanship. 

Thanks @Bfg it’s a craft I’m determined to master - weld number 5 is scheduled for Sunday - your advice will help a lot.

[Pettifordo]

So this is the result of todays welding adventure.

I tried to take on board all the advice and I think the result looks better. It a nice strong result. On the down side I found more holes that need filling 🤣🤣🤣

I guess on the positive side it means I get more practice.

I did add a couple of self tapping screw - although it took a few mins to sort them out I think it made me more confident with the welding.

One thing I focused on was using both hands to control the welding torch and to focus on not being “pushed back” at the start of the weld or move away quickly at the end - it definitely helped.

I also set the welding mask to 10 instead of 12 and I think this made it easier to see the weld pool.

I suspect that I could have had the welder turned up a small amount as I still ended up with pigeon s**t welds which were quiet proud (hence the grinding) - but the penetration looks ok. Perhaps I’m also holding the trigger for a second too long ??? Or need reduced wire feed ???

With the gas turned up to 12 and everything clean I was getting a good consistent “sizzle” sound which was good.

 

 

[Bfg]

You've done really well.  That looks a huge improvement and the patch also looks to be well and truly flat to the surface. 

Tip :  cover over (even if just with gaffer tape) or else put an old bolt in, adjacent threaded holes - as sometimes splatter &'or grinding ends up in there ..and is a pig to get out again. 

I don't know if you have two grinders. I have a small one which I use grinding discs on, and then also a variable speed polishing / linishing machine. It's big and heavy but quite controllable, not least because I can turn its speed right the way down.   I often use the grinder (coarse cutting) to take high spots off the welds ..very accurately and then the linisher to finish things smoother. 

You may also consider whether you need so many tack welds. That might be best ascertained on a test piece which you weld just a couple of tacks and then try to rip apart.!  A good weld is incredibly strong.    A few spots have missed target ..which may be a matter of requiring better lighting, or your position to better see around the shroud.  I know that's often not easy ..when working under a wheel-arch or when contorted within the boot of a car.  Perhaps you might try tacks to get things held in place and then short strips of weld inbetween those.  Let each weld cool down inbetween times by working diagonally around the patch.

Although this gearbox cover needs to be a barrier against noise, fumes and heat into the car, it didn't need any more weld than these.  The join is an overlap and so there are also tacks inside, offset from these, so it's very strong.  After painting primer into the overlap, I seam sealed it inside and out.

As an example of mostly working from one side. With the following I did just a few tacks on the outside, to accurately align and hold things together, and then most of the welding inside. I later ran the angle grinder over the high spots, but it wasn't necessary in this circumstance (under the gearbox cover) to try for a really flush finish . .

  

 

On 09/01/2022 at 18:18, Pettifordo said:

I suspect that I could have had the welder turned up a small amount as I still ended up with pigeon s**t welds which were quiet proud (hence the grinding) - but the penetration looks ok. Perhaps I’m also holding the trigger for a second too long ??? Or need reduced wire feed ???

Like diagnosing a car's poor running or starting fault, its always best to only change one setting at a time ..then retest. 

I too think you could turn the power up just a tad. However.., you'll also find that when you turn the wire-feed speed down - the metal fuses together a little longer before the weld builds up.  I would try that before you alter the power setting.  The feed however should be just enough to prevent the wire melting back to the tip.  

Again I'm not criticising, I'm just trying to offer a few pointers,

Pete

[Josef]

36 minutes ago, Bfg said:

You may also consider whether you need so many spot welds. That might be best ascertained on a test piece which you weld just a couple of tacks and then try to rip apart.!  A good weld is incredibly strong.    A few spots have missed target ..which may be a matter of requiring better lighting, or you positioning yourself to see around the shroud.  I know it's not easy when working under a wheel-arch or when contorted within the boot of a car.  Might I suggest you try tacks and then short strips of weld inbetween those.

However, given this repair is right next to a seat belt mounting it is most definitely structural and as such must be continuously welded to be road / MOT legal. Now if it’s tacked / stitched on one side and continuously welded on the other then it’d technically be passable I’d think, but I’d personally rather not risk ever having to have that argument with a tester!

Having said that my Spitfire went through ~20 years of MOTs before I bought it with structural ‘repairs’ consisting of everything from brazing down to silicone bathroom sealant and expanda foam… So realistically the chances of a fuss being made are probably minimal. 

[Josef]

Also, while we’re on it @chrishawley, what’s the (or even a) proper name for the technique you demonstrated of building a continuous weld from multiple overlapping tacks? I thought it was stitch welding, but that’s what Pete is demonstrating on the overlap joints on his tunnel above (short weld, gap, short weld etc).

[Bfg]

 

Regarding the structural needs of seat belt anchorages, I do not disagree with regard to MOT requirements.  Structurally though it's a very different matter.

Spot welding usually refers to localised pressure and electrical resistance welding at points clear of the edges of thin sheet.  Plug or slot welding is of course having pre-drilled / pre-stamped hole through one piece and then filling that with welding wire or rod being fused to the second piece.  So what we've been discussing / demonstrating are simply edge tack welds. They are quickest and easiest for a novice and/or for thin sheet / rust thinned metal, as each tack is allowed to cool down ..and so blow-holes and distortion are minimised.  I would assume Chris's weld would be 'contiguous tack welding'. 

Stitch welding is very commonly specified for structural Civil Engineering work (where I started my career).  Its strength and longevity is required but it's not necessary to seal the seam, such as would be necessary with a yacht's water tank.  Typically stitch welding is specified as the number of welds, the length of weld and the space between welds, for example 6x20x30 specifies six welds, each of 20mm long followed by no weld for 30mm.  The number of welds is omitted as when all around is indicated, such as around a perimeter, or throughout the length of a beam.  As far as I'm aware, it's not usual to specify stitch welding with tacks, but the tacks are useful for holding everything firmly in place, because if someone starts welding (either continuous or stitch) from one end ..then by the time they get to the other end the alignment will most likely have wandered and straightness will have bowed.

  

[Pettifordo]

Do any Spitfires need MOTs now ?

My car was manufactured in 1980 and it is registered as an Historic Vehicle - so no tax and no MOT.

That having been said I believe that even without the need for a MOT I do have a responsibility to make sure the car is in good / safe working order.

I was planning to take it to get MOT’d anyway so I guess I need to seam weld this side as well - let’s hope for less pigeon s**t - or a better angle grinder 🤣🤣🤣🤣🤣

[Bfg]

On 10/01/2022 at 19:10, Josef said:

if it’s tacked / stitched on one side and continuously welded on the other then it’d technically be passable I’d think

 

11 hours ago, Mathew said:

Although the welds are like spots, they have been done in a continuous line and i would of thought would be considered as a seam weld.

 

Agreed as Josef and Mathew have noted.

 

On 10/01/2022 at 18:02, Bfg said:

You may also consider whether you need so many tack welds.

My point was that you have continuous weld on the underside, next to the captive nut, which satisfies both the structural and MOT safety requirement. 

And so., the number of tacks on the inside needed only be enough to hold the patch flush / in place while you welded underneath.  And as that might have only been five or six tacks (inside the car) then it would have saved you a whole lot of work in welding and subsequent grinding.  This is what I had hoped to illustrate in my second example (2nd & 3rd photos).

- - -

In reality though, you have to satisfy yourself.  As you are ultimately responsible for the structural integrity of the repair.  And so I suggested you make a test piece ..and try testing those welds (to destruction !) to get a hands-on feel  for how really strong a couple of good welds are  ..not least compared with what a collar bone, body and/or neck can take in g-force deceleration.  if those welds can take double your body weight then that's already got a 100% safety margin !

Now, if that's just a couple of good tacks, imagine how much more the continuous welded plate will take !   So yes, please do observe the legal requirements, as you have now done on the underside, and then finish cleaning things up, fill & paint, or trim over, under-seal inside and out ..as you would normally do.   Not to hide anything, but just because that's what you want to see as a finished repair.  An MOT inspector may tap it, or may push against any suspect areas to see if it flexes, and may in some instances even use a magnet to ensure there is steel rather than just bondo in the repair, but he will not scrape the paint off, nor remove interior trim to check it.  The onus is on yourself to ensure that you are comfortable with its strength.

- - -

On 10/01/2022 at 18:02, Bfg said:

Perhaps you might try tacks to get things held in place and then short strips of weld inbetween those. 

What I'm saying here is, with just half a dozen tacks on inside the car to ensure the plate is positioned and tight against the surface, then you might do the same on the underside. If you were to space those tack welds every 3/4" (20mm) around the underside perimeter, then the stitch-welds between those (to make it a continuous weld) will also only 3/4" (20mm) long.  And because the plate is overlapped rather than edge to edge, they ought not burn through.  I think you may find those short stitches, to join-the-dots (tack welds), easier than the contiguous tack welds shown by Chris..  Tbh, that's pretty neat work he's doing there .. with accurate positioning at a very controlled pace.    

Pete

[chrishawley]

On 10/01/2022 at 19:13, Josef said:

Also, while we’re on it @chrishawley, what’s the (or even a) proper name for the technique you demonstrated ....

I've never known a proper name for this technique. Of all the technical aspects of welding that have definitional standards I can't find one for this. Would be really helpful to have a proper name fo it if anyone knew.

[chrishawley]

Pettifordo>> Glad you are making progress on the welding. I think you mentioned a few posts back that you were sometimes getting very 'high' or 'knobbly' welds. Sometimes one sees welding where the result looks a bit like someone has glued petit pois onto the metal (or rabbit pellets). I'd never reallt thought about this much so I had a play ot see if I could understand it.

#1 in the photo shows a strike where the heat was just a little on the low side and I deliberately kept the duration short. High build of wire on the working side of the work and only minimally adequate penetration of the reverse.

#2 show same heat setting but now a deliberatley too long duration: Much less build on the working side but at the expense of excessive penetration on the reverse.

#3: Now using a higher heat setting the with right (fairly short) duration. Close to ideal - quite flat on the work side, well melted in, and a nice penetration on the reverse.

My deductuion is that 'petit pois' welds are an interaction of heat that is relatively low (in relation to the work in question) and a relatively short pulse. I experimented with altering the wire speed but that made no significant difference (the 'sizzle' range is pretty narrow anyway).

If I recall, you're opting mainly for lap welds rather than butt welds. But a lap weld (for a given thickness of metal) requires more heat than a butt weld because one is, in effect, welding a piece that's twice the thickness. For a butt I usually use setting 1 on my machine for 0.8 - 1.0mm steel. But for a lap or a plug weld I'll step up to 2 or even 3.

Hope you continue to make good progress.

[Pettifordo]

So the suspension tunnel from Chic Doig is now in the car.

Using the spot weld head for my MIG welder which is also now on a trolley 😋

Took 3 test fits before I then used self tapping screws to get the surfaces really close.

I’m pleased with the results

[chrishawley]

Glad to see you are making good progress. Your 'photos are excellent quality and it's possible to really see the nitty gritty of what's going on.

I've just posted a item which might be relevant to you,  see 'Replacing spot welded panels. Plug or Push tecnique?'

Looking around the 'photos I can't say I have much confidence in PO's previous welded repairs. There are a lot of edges that simply aren't welded and patching over a rusty area is a no-no. I'd suspect that a lot of the previos will need to be excised and done again properly.

[Pettifordo]

14 hours ago, chrishawley said:

Looking around the 'photos I can't say I have much confidence in PO's previous welded repairs. There are a lot of edges that simply aren't welded and patching over a rusty area is a no-no. I'd suspect that a lot of the previos will need to be excised and done again properly.

Yes it is taking some time to take out what has been done previously ! With hindsight I would have replace the rear wheel arches and the rear floor….but I think I can get it structurally sound even if it isn’t pretty !! When I have been welding I have been doing it back to bare / good metal and I will continue with this process.

this is the worst part of the car as the rear wings, rear valance and sills have been done before. The floor is a patchwork of previous repairs so these are being replaced with new front to back - I will just have to show that part to people and not the back !!

On Saturday I spent time getting the join between the suspension tunnel and to floor looking good only to realise that it was going to be covered by trim - at least I know it looks ok 🤣🤣🤣

 

[Josef]

The bits only you will ever see are good practice for the rest though! So spending time making hidden bits look good is definitely not time wasted in my book

Are you at least only having to remove old welded on patches? Cutting out brazing was one of my least favourite jobs… Though the brass dust everywhere looked quite pretty  

[Pettifordo]

3 hours ago, Josef said:

Though the brass dust everywhere looked quite pretty  

🤣🤣🤣🤣🤣

I will make it look as good as possible.

This is my first resto project so I definitely want to learn and get better.

I’m already looking at my first efforts and thinking about cutting them out and redoing them 🧐🧐

One of the best tips from this site was to get good light on the area - makes a big difference to welding in the right place - I got a tripod for my 2x1000lm work lights so I can bright light from above - really great and it only cost £18 on Amazon 👍👍👍

Floodlight Tripod Stand,Twin Head 150cm Adjustable Telescopic LED Work Light Tripod Stand for Job Site Lighting Mount Work Lamp Lighting Bracket - Mount 1 to 2 Lights https://smile.amazon.co.uk/dp/B09KNHXGNV/ref=cm_sw_r_cp_api_glt_i_VJFTW68FS0QADZVTYPSJ?_encoding=UTF8&psc=1

[Brooky]

Always test your reactive helmet by looking at lighting before welding. Also, each time before starting to weld, snip your end of mig wire for a fresh strike every time, practice and practice and practice on some spare steel 😎