No it's not but made much easier with a hard top. I always have the car sitting on its wheels and the doors on when doing sills. I saw a video of mx5 sills being done on a roll over frame. Boy is that asking for trouble.
Some very useful tips here, but I have a question. Why use Zinc primer, rather than copper? Zinc has a boiling point of 907*C Copper has a boiling point of 2562*C From my experience, Copper is a much safer primer option for plug welding over Zinc, and should protect better from corrosion forming around the weld
Good comment. I had to do some research as I didn't know why there are copper and zinc options. I've used both over the years but I've used zinc way more than copper. From my research zinc is better at protecting the steel from corrosion as it provides a sacrificial coating, just like galvanising or zinc plating. Corrosion attacks the zinc and not the steel when in contact with an electrolyte. Zinc rich weld through primers do spit a bit more and copper less so. From what I've read copper is better for welding but not so good as an anticorrosive. The low melting point of zinc allows it to flow around the plug weld and coat the inside. Feel free to correct me and thanks for bringing it up as I've learnt something.
@@bensclassicbodywork Both work as a sacrificial barrier to corrosion, but you have to consider that Zinc will mostly evaporate due to the heat from the weld. Typically 1000-1100*C. Effectively leaving you with little to no protection around the weld. Copper won’t flash off till 2500+*C and has a higher melting point, allowing it to “pool” around the weld as you described. Zinc would be better suited to pinch welding, as the heat generated it a lot less and in a much smaller area. For plug welding Copper is definitely the way to go as you need a decent bit of heat and typically have much larger surface area
@@UP4U I've just watched a video comparing the two with regard to the boiling point and it makes perfect sense that the zinc would evaporate away during the welding process. There are some forums saying that copper accelerates rust and zinc prevents it. I suspect this isn't correct as they wouldn't sell copper advertised as an anticorrosive. I looked at the upol data sheets and copper vs zinc. Both are advertised as suitable for mig welding. Very little data on those sheets and it didn't explain anything. I would guess that copper is better around the weld and zinc is better for the non welded areas? I'm guessing as I don't know the answer.
@@bensclassicbodywork I'm unconvinced that either work when used as a "weld through" material - welding burns both away, leaving bare steel. It's kinda kidding ourselves that painting the back of weld areas before welding works. The only thing that works is treating after welding is completed. I see lads painting seams then spot-welding them - wherever they weld, it's gonna rust as the heat from welding sends all & every coating right off into the ether. I also believe only oil or grease based products work as "after-treatment" to the backside of welded areas - I am unconvinced by anything else. They look pretty for a while, the paints & suchlike, but chances are pretty for a while is about the height of it. Oil & greases tend to be long-term, despite how non-pretty they appear.
@@jamesward5721 yes, I think getting cavity wax in the joints or if that's not possible then tiger seal the joints. Both take away the air and stop moister getting in. The weld through primers wouldn't last long exposed to the elements. They are just an added thing that is better than nothing I would say.
Well, you certainly do like to keep yourself busy !! :) I take it this is your day job then and not building helicopters ? :D :D :D Welding is one of those things I've always fancied learning to do, it looks like useful skill to have. I can work with wood but metal work other than the most basic has always eluded me. One of my paragliding buddies is a hoof trimmer by trade, mostly cows but horses too and he's invented and built the craziest machine attached to a truck that picks a cow up and rolls it on its side so he can safely trim their hooves. I couldn't believe what I was seeing... proper Wallace and Grommet ! but done well, and without the cheese :) What is it about the English man and inventing things in their sheds ? :)
👍 Yes, it's my day job but I started as an engineering apprentice, the cars were just a hobby that became my profession. Your mate that made a cow/horse rotisserie sounds amazing. Working with wood isn't something I've done a lot of, one of the reasons I would shy away from wooden rotor blades but as you know it's an excellent material for the purpose. I'm completely at home with metals.
@@bensclassicbodywork .. You're clearly very skilled with your machining and metal works !! I did wonder about using a nice dense and strong hard wood for the leading edge of the blade and foam core for the trailing edge with a carbon fiber shear web between the two, skinned with carbon fibre and possibly a protective glass fibre over that. Not sure if it would be any cheaper than ali though.
Good tips 👍🏻
Bad tips
thx for the tips, i hope i can finish my gt junior oneday 🙂
👌 nice car, what stage are you at with it ?
@@bensclassicbodywork thx, i welded the trunkfloor , now i need to change all seals both sides , innerseals inclueded :( , thats not an easy job
No it's not but made much easier with a hard top. I always have the car sitting on its wheels and the doors on when doing sills. I saw a video of mx5 sills being done on a roll over frame. Boy is that asking for trouble.
Some very useful tips here, but I have a question. Why use Zinc primer, rather than copper?
Zinc has a boiling point of 907*C
Copper has a boiling point of 2562*C
From my experience, Copper is a much safer primer option for plug welding over Zinc, and should protect better from corrosion forming around the weld
Good comment. I had to do some research as I didn't know why there are copper and zinc options. I've used both over the years but I've used zinc way more than copper. From my research zinc is better at protecting the steel from corrosion as it provides a sacrificial coating, just like galvanising or zinc plating. Corrosion attacks the zinc and not the steel when in contact with an electrolyte. Zinc rich weld through primers do spit a bit more and copper less so. From what I've read copper is better for welding but not so good as an anticorrosive.
The low melting point of zinc allows it to flow around the plug weld and coat the inside.
Feel free to correct me and thanks for bringing it up as I've learnt something.
@@bensclassicbodywork Both work as a sacrificial barrier to corrosion, but you have to consider that Zinc will mostly evaporate due to the heat from the weld. Typically 1000-1100*C. Effectively leaving you with little to no protection around the weld.
Copper won’t flash off till 2500+*C and has a higher melting point, allowing it to “pool” around the weld as you described.
Zinc would be better suited to pinch welding, as the heat generated it a lot less and in a much smaller area. For plug welding Copper is definitely the way to go as you need a decent bit of heat and typically have much larger surface area
@@UP4U I've just watched a video comparing the two with regard to the boiling point and it makes perfect sense that the zinc would evaporate away during the welding process.
There are some forums saying that copper accelerates rust and zinc prevents it. I suspect this isn't correct as they wouldn't sell copper advertised as an anticorrosive.
I looked at the upol data sheets and copper vs zinc. Both are advertised as suitable for mig welding. Very little data on those sheets and it didn't explain anything.
I would guess that copper is better around the weld and zinc is better for the non welded areas? I'm guessing as I don't know the answer.
@@bensclassicbodywork I'm unconvinced that either work when used as a "weld through" material - welding burns both away, leaving bare steel. It's kinda kidding ourselves that painting the back of weld areas before welding works. The only thing that works is treating after welding is completed. I see lads painting seams then spot-welding them - wherever they weld, it's gonna rust as the heat from welding sends all & every coating right off into the ether. I also believe only oil or grease based products work as "after-treatment" to the backside of welded areas - I am unconvinced by anything else. They look pretty for a while, the paints & suchlike, but chances are pretty for a while is about the height of it. Oil & greases tend to be long-term, despite how non-pretty they appear.
@@jamesward5721 yes, I think getting cavity wax in the joints or if that's not possible then tiger seal the joints. Both take away the air and stop moister getting in. The weld through primers wouldn't last long exposed to the elements. They are just an added thing that is better than nothing I would say.
Well, you certainly do like to keep yourself busy !! :)
I take it this is your day job then and not building helicopters ? :D :D :D
Welding is one of those things I've always fancied learning to do, it looks like useful skill to have. I can work with wood but metal work other than the most basic has always eluded me. One of my paragliding buddies is a hoof trimmer by trade, mostly cows but horses too and he's invented and built the craziest machine attached to a truck that picks a cow up and rolls it on its side so he can safely trim their hooves. I couldn't believe what I was seeing...
proper Wallace and Grommet ! but done well, and without the cheese :)
What is it about the English man and inventing things in their sheds ? :)
👍 Yes, it's my day job but I started as an engineering apprentice, the cars were just a hobby that became my profession.
Your mate that made a cow/horse rotisserie sounds amazing.
Working with wood isn't something I've done a lot of, one of the reasons I would shy away from wooden rotor blades but as you know it's an excellent material for the purpose. I'm completely at home with metals.
@@bensclassicbodywork ..
You're clearly very skilled with your machining and metal works !!
I did wonder about using a nice dense and strong hard wood for the leading edge of the blade and foam core for the trailing edge with a carbon fiber shear web between the two, skinned with carbon fibre and possibly a protective glass fibre over that.
Not sure if it would be any cheaper than ali though.
WRONG
@@VaclavVanoucek oooh, my first negative comment. Care to elaborate on what is wrong ?
@bensclassicbodywork In fact, nothing sorry, I was watching the video in my work at first and I didn't hear some stuff you said. My bad
@@VaclavVanoucek 🙂 no worries. 👍