Question for PiPUK re Layering LSPs

[ski2]

Layering LSPs is a common practice for looks or more durability. However, some have said it's of no value as both deteriorate chemically at the same rate despite one being either on the top or bottom.

It would seem that the LSP on top would deteriorate first as it's exposed to the elements, polution, soaps etc.

Would be interested to hear your take on this subject!!!

[PiPUK]

Hey there,

It is a good question but not trivial. Of course we have different types of LSP so lets look at them, individually. I should note that this is theory and variations with products mean that there will be exceptions.

Wax
Without specialist additives, waxes do not really bond to a surface. What bond exists is rather weak. With a wax, IMO, the biggest issue from multiple layers is that you eventually risk almost pulling off the underlying wax when applying over the top. Making it thicker does nothing at all to enhance the bond to the surface but it does mean you have more wax. In theory, the wax is generally degraded from the top down as it 'reacts' with the environment and cleaners. So, in theory, more means that it takes longer to react away what is present.

Sealant
These do (should!) form a moderate bond to the surface. I would suggest that most should not be too picky about what they bond to so they should bond well to themselves. You are not going to be applying as much material as with a wax and, with the stronger bond, you won't really have to worry about de-laminate the underlying layer. Again, with more layers and a top down removal, you should have good benefit with durability.

Super sealants
Almost impossible to discuss here because it depends whether they are non-specific (or not) in their bonding. Some products will not bond too well to themselves but, if they fit with the 'type' they should have a very strong bond to the surface and multiple layers should do nothing assuming you have full coverage (and layers should be so thin as not to alter optical behaviour, as the previous two could).

Much of this assumes removal from the top down. Some people seem to think it happens the other way round but that would suggest something wrong with the surface that meant the LSP was extremely loosely attached and the reality would be that such a thing would still require some force on the top to remove it.

My view, a couple of thin layers of wax are probably fine and should enhance durability and optics. Sealants you can layer away to your hearts content and it should get better with each layer (unless you apply daft amounts!). Super sealants should be single layers, if they need multiple layers, then they either are not so super or coverage was not adequate.

Hope that helps a little.

[swanicyouth]

I think the best "layering" is wax over a cured sealant. Best of both worlds. Hover, dunno if the solvents in a wax could affect a sealant. I doubt it though if the wax isn't harmed by it (completely wiped off the surface when buffed off).

[PiPUK]

There should not be a great issue with wax over sealant but I assume that your motivation would be to get 'wax appearance'? I would expect sealant over sealant would give superior durability.

[ski2]

Thanks for the reply PiPuk! It just made sense to me that layers of LSPs would deteriorate from the top down and was curious to see if you had knowledge that contradicted that conclusion.

Without having done any controlled testing, but just everyday observations it seems clear that layering (to a point) increases durability. Over the years of trying different LSPs it has always appeared that the top layer would wear away first.

Currently I'm using a sealant as a base coat that has a reputation of great durability and has noticable characteristics. I top it with a hybrid sealant/wax that has less durability (but a great look) and it's own characteristics much different than the base sealant. As the top coat begins to fade it's very easy to see the characteristics of the base layer beginning to emerge so it's time to add another coat of the top coat. When that begins to fade the base layer characteristics continue to emerge. I found if I add another top coat before the first one fades totally the base layer seems to last a year or more. As you mentioned even layering pure sealants seems to increase durability--I know of a meticulous detailer who applies FK1000P then adds a second coat a week later and gets over a year of protection from just those two coats.