Undercoating

[kevstens]

About 2 weeks ago I sprayed Wurth SKS Stoneguard undercoating on my 69 911E. Everything looked good. As the coating dried it began to flatten out. It now does not have much texture. I called Wurth to ask about what happened al was told that Stoneguard does not have much texture. I have used it in the past and it turned out great.
I asked if I could shoot another coat over what I already sprayed and was told I should remove the coating on the car and try to spray a heavier coat. There is no way I want to remove the coating I just shot on.
Does anyone have any thoughts on what I should do?

[Eljimberino]

There should be texture.

Can't see why putting another layer on would hurt.

But removing two layers would be a real pain.

Dry ice is the best way to remove it.

Do you have a photo?

[962porsche]

most likely the reason why Wurth is telling to to strip the chip/stone guard back off is because you have exceeded the Micron build of the product. by doing so you will run into problems later on down the road with things like bad adhesion easily chipping and delaminating.

sadly there is no easy clean low cost or fun way to remove stone guard.
should you remove it?
if you applied two coats and are at or over the 150 microns per coat totaling more than 300 for two coats and even more so if you applied it over an existing stone guard that was on the car already.

dry ice is one way but not a way that is low cost or very easy if you do not have the equipment already.
you can use a air scraper and scaler tools this does work good and is pretty quick way to strip the stone guard off.
we also use rotary removal tools with wire wheels on them. this does rip the stone guard right off the car but makes a nice mess doing so.
none of the tools are all low cost to buy.
some thing like the Dynabrade nitrozip tool will run you about 300$ a good air scraper will be about 150$ along with a good air scaler tool.
you can buy a air scraper tool at Harbor freight for about 30$ but they do not have a very long stroke to them and not a lot of balls.
I just did all the stone guard removal on a 944 that's the wheel houses, underside of the car and rockers using a rotary strip tool and air scraper took me 8.3 hours to do the hole car.

you have to put in the texture your looking for when you spray the product.
personally I like U-pol stone guard and I use a gun that I can adjust every thing from air pressure , product volume and spray pattern. sadly the CO that made my gun is no longer in business but it's the same basic gun you use for Lizard skin.
you can use the regular stone guard guns but it's harder to control the product your.
to get more texture out of your regular gun.
you need to turn down the air pressure and pull the gun away for the panel more and the gun speed should be faster.
this will make the droplets coming out o the gun bigger and moving faster will spread them apart more.
you will want to do a spray out to see how the product is laying down. do not do a spray out on things like cardboard that will soak up the solvents. do it on metal ,plastic, glass anything that will not soak up the solvents from the stone guard.

once you get the desired texture with your stone guard if you have to paint it do not spray a primer over it. this will take away much of the texture in the stone guard. if you have to paint it only spray a sealer over the stone guard. sealer does not have the same mil build as primers and will give you the proper adhesion for your top coats to stick to.