Wolverhampton Garage

[winston]

1 of them is back and ironically the 1 that asked the question 🙄

This topic, doesn't need any further discussion.

[BN]

4995 back from paint, replaced with 4990.

[Tony]

4995 back from paint, replaced with 4990.

Refurb on 4986 finally finished as well, I'm taking it to underseal on Monday,  should be painted second half of next week ready for MoT prep

[Mayfield]

I know what underseal is but why does it need doing on a bus this old

[Tony]

I know what underseal is but why does it need doing on a bus this old

Why do you think?

To stop road salt rotting the chassis same as any other vehicle 

[Mayfield]

Can't seem to get an answer on this forum without a snide comment to go with it, vehicles are under sealed from new and it's lasts the life so why does it need doing again, simple enough question, don't even bother answering it if it can't be done without the aside.

[Tony]

Can't seem to get an answer on this forum without a snide comment to go with it, vehicles are under sealed from new and it's lasts the life so why does it need doing again, simple enough question, don't even bother answering it if it can't be done without the aside.

It doesn't last a lifetime far from it, all NX buses are undersealed at every refurb for that very reason. 

If it lasted a lifetime vehicles of any type would not go have to be scrapped because they were rotting 

[Squiz1971]

Refurb on 4986 finally finished as well, I'm taking it to underseal on Monday,  should be painted second half of next week ready for MoT prep

I take it this is something that cannot be done inhouse or at the paint shop @Tony? Or is it just easier to get it done elsewhere?

[Tony]

I take it this is something that cannot be done inhouse or at the paint shop @Tony? Or is it just easier to get it done elsewhere?

It could be done in house, the new PB garage has a chassis cleaning facility which could be used, but there's a place in Aldridge that has been doing all NX buses at refurb for many years and continues to do so.

[MW]

It could be done in house, the new PB garage has a chassis cleaning facility which could be used, but there's a place in Aldridge that has been doing all NX buses at refurb for many years and continues to do so.

Is that roughly every 5 years that buses are undersealed?

[2900]

would'nt galvanising  the chassis from new be far more effective than powder coating and under sealing

[Wumpty]

would'nt galvanising  the chassis from new be far more effective than powder coating and under sealing

Unfortunately not.

Galvanising provides an average of 5 years "moderate protection". Galv will also suffer from white rust where it is exposed to prolonged moisture and road salt, leaving a white powdery residue on the surface. Undersealing and chassis treatment with further protect and treat the metal work, but nothing will definitively protect steel from the inevitable rot.

[winston]

Unfortunately not.

Galvanising provides an average of 5 years "moderate protection". Galv will also suffer from white rust where it is exposed to prolonged moisture and road salt, leaving a white powdery residue on the surface. Undersealing and chassis treatment with further protect and treat the metal work, but nothing will definitively protect steel from the inevitable rot.

No it doesn't, galvanising comes with 20 year guarantee for corrosion protection. 

Stainless Steel is another option, although you will get bi-metallic corrosion when dissimilar metals are bolted to a stainless steel chassis without being isolated. 

This is why railings at the seaside are either galvanised or stainless steel, because they are in a highly corrosive environment with salt water. 

[Wumpty]

No it doesn't, galvanising comes with 20 year guarantee for corrosion protection.

Stainless Steel is another option, although you will get bi-metallic corrosion when dissimilar metals are bolted to a stainless steel chassis without being isolated.

This is why railings at the seaside are either galvanised or stainless steel, because they are in a highly corrosive environment with salt water

@winston the basic DX51D+Z coating is "expected to perform" for 20 years - there is no guarantee on this. The warranty period for this is 5 years where it is expected to provide 99% protection with no visible/structural defect. Generally speaking, the thicker the steel, the heavier the coating, though there are other factors to consider depending upon its forming/structural applications, or if the steel was coated at the time it was produced in coil/bar form, or retrospectively coated after fabrication by a galvanizers.

Railings nearer to the coastline usually have heavier galv coating to provide additional protection from the elements. This again, comes with its own flaws as the heavier the coating and inclement/corrosive environment, the more susceptible to white rust it is.

This was the mainstay of my 15 years in the steel industry and having to deal with claims for underperforming hot dipped galzanize coating. Anything that was mill coated we'd be able to definitively answer; anything hot dipped after fabrication we'd refer to the galvanizers.

[winston]

@winston the basic DX51D+Z coating is "expected to perform" for 20 years - there is no guarantee on this. The warranty period for this is 5 years where it is expected to provide 99% protection with no visible/structural defect. Generally speaking, the thicker the steel, the heavier the coating, though there are other factors to consider depending upon its forming/structural applications, or if the steel was coated at the time it was produced in coil/bar form, or retrospectively coated after fabrication by a galvanizers.

Railings nearer to the coastline usually have heavier galv coating to provide additional protection from the elements. This again, comes with its own flaws as the heavier the coating and inclement/corrosive environment, the more susceptible to white rust it is.

This was the mainstay of my 15 years in the steel industry and having to deal with claims for underperforming hot dipped galzanize coating. Anything that was mill coated we'd be able to definitively answer; anything hot dipped after fabrication we'd refer to the galvanizers.

Text extracts taken off the following Galvanizers website:

"Hot dip galvanizing
A coating that lasts up to 100 years"

https://www.josephash.co.uk/services/galvanizing/

"A hot dip galvanized finish gives steel a long life and durability of between 34 and 170 years, depending on the environment. In addition, it creates a maintenance-free finish, which lessens the carbon emissions usually associated with the upkeep of non-galvanized steel"

https://www.josephash.co.uk/blogs/excellent-reasons-to-hot-dip-galvanize-steel/