DIY - Custom Stone Guards
04-14-2013, 07:35 PM
#1
Racer
Thread Starter
DIY - Custom Stone Guards
DIY - Custom Stone Guards
In this DIY I will show how I made some custom stone guards for my 1997 Porsche 993.
First, the backstory. I had some body work done on my car which resulted in the
left side being repainted, including the rear bumper cover. This necessitated replacing
the left side stone guard which was the Arctic Silver painted style. The old guards were
quite beat up, so I was looking forward to refreshing them. With 15 years of rock hits,
there were lots of little black specks in the painted top coat. The new guards were an
instant improvement, but upon closer inspection, there were white blotches under both
guards which appeared to be manufacturing defects. But of a more serious note was
the fact that the body shop didn't quite get the curvature of the rear fender right at the
bumper cover line so it was sent back for a redo.
This time they got the curve right, but now Porsche had run out of stock on the painted
guards and had decided to obsolete them. OK, I had been thinking that maybe the clear
guards would be a better idea in the long run anyway. So we order up a set. The first
set had one that was damaged so it was reordered. It came in damaged so another
one was ordered. Eventually we got a set without imperfections and they were installed.
But, the installer managed to tilt the one on the left side and not get it on
straight.
But there's more. The rear bumper cover was repainted and the years of road rash
behind the wheel on the leading edge of the bumper cover was corrected with new paint.
So I thought now would be a good time to protect this edge with paint protection
film (PPF). I found a shop that installed PPF and asked them to install some protection
for this edge. They suggested I use a pattern from their catalog for low cost. I said OK.
But I later found out that it did not cover the entire exposed area behind the wheel.
So, I located another shop and explained I wanted to have complete coverage behind
the wheel so there would be no road rash. He said he had 5 catalogs of patterns but
none of them provided complete coverage. He attempted a custom replacement of
what I had, but in the end did an incompetent job on one side where he goofed the curvature.
Fed up with all this, I decided to learn how to make stone guards and install them myself.
Overview of the Process
Photos that illustrate this DIY can be found here:
https://picasaweb.google.com/bruce.c...r75fvCt_TQ4AE#
I only wish I had 3 hands or an assistant to get more photos to document the process better.
The process to create a stone guard is only a few straight-forward steps.
The rest of this DIY will discuss each of these steps.
Tools Needed
Steam canister, e.g. McCulloch MC1275
2 spray bottles
4 inch rubber squeegee
plastic hard card
Dual-Action polisher and a light abrasive polisher such as #80 Speed Glaze
To create patterns you will need Adobe Illustrator and a scanner.
Materials Needed
New stone guards
Johnson & Johnson Baby Shampoo
70% Isopropyl Alcohol
distilled water
microfiber towels
paper towels
3M general purpose adhesive remover
Making the Fender Stone Guard Pattern
I took one of the original Porsche stone guards before installation and scanned it
at 100% on a Xerox machine. Because the stone guard was too large to scan all at
once, I made two alignment marks with a pen. Then I scanned the top half and bottom
half separately. The Xerox will output a .jpg file of the scan.
The two .jpg files were then brought into Adobe illustrator and merged using the
alignment marks. Next I traced the outline and then output a vector file.
You only need to do this for one side as the other side can be easily mirrored in Adobe
Illustrator.
Making the Bumper Stone Guard Pattern
To make the bumper stone guard pattern, I used a tape mask technique. Using blue
painters tape, I taped the area I wanted to cover with PPF. I laid down 2-3 layers of
tape being careful to make good clean edges. I then lifted the entire tape mask off
and placed it onto a piece of paper.
The tape mask was then scanned in whole on the Xerox machine. Then, as before,
the .jpg file was brought into Adobe Illustrator, traced and a vector output file created.
Selecting the Paint Protection Film and Getting the Patterns Cut
One of the advantages of this process is that you can choose from a number of PPF
products to make the stone guard from. I talked with Dean at Sticker City in Van Nuys,
about my options and chose 3M VentureShield which is 8 mil PPF.
Aware that Porsche specified 12 mil PPF, I was initially concerned whether or not 8 mil
would be sufficient. I'm pretty much convinced that it is and if it weren't, you can bet a
business like Sticker City would not be using it. But just to test the idea myself, I decided
to leave the Porsche 12 mil stone guard on the right side alone and that way after a
year or so I can compare.
Visually the 8 mil VentureShield is a little less obvious than the 12 mil Porsche guard.
By the way, did you know that in the five catalogs I mentioned earlier that not one
of them has an exact match for the Porsche fender stone guard? Yet another reason for
going this route.
Having chosen the PPF stock, I handed my patterns over to Dean via my Porsche
USB drive. He set up the Graphtec plotter and cut-out the stone guards, providing me
my new guards all rolled up and packaged in a sealed plastic bag.
Now, you want to be careful not to damage the guards before installing them.
Don't be like Porsche and crease the guard or damage it in some way.
Removing the Old Stone Guards
Steam is your friend. I used a McCulloch MC1275 steam canister to remove the old
stone guards. These tools are about $125 and can do a lot more than just remove old
stone guards. They can be used for car detailing and they can be used for installing
PPF as well as removing PPF. They also have other uses around the house.
Use lots of steam. Lift up a corner of the film with a fingernail and pull the film off the
car at a 90 degree angle. Don't go too fast, be sure to apply lots of steam to soften and
loosen the film before pulling on it.
If you encounter peeling paint with the removal, see the section below on problems
and what to do. It is not normal to have paint peel off with the PPF.
After the PPF is removed, clean the surface of the panel to remove old glue residue
and wax. 3M General Purpose Adhesive Remover generally works well enough. Some tough
glues may need gasoline to help soften and remove. Afterwards, use a dual-action
polisher to polish the surface of the clear coat and wipe down. I like Meguiar's
products
and used #80 Speed Glaze on a yellow pad with a Meguiar's DA polisher.
Preparing to Install
You are going to need two solutions to apply the new PPF.
Slip Solution
Fill spray bottle with distilled water. Add 6 drops of Johnson & Johnson Baby Shampoo.
Shake to mix the solution.
Alcohol Solution
Fill spray bottle halfway with 70% Isopropyl alcohol. Fill the remaining half with
distilled water. Shake to mix.
Squeegee
Before the first time the rubber squeegee is used it should be boiled in water
for 1 minute to help soften it. It must be soft not hard or it will mark the film.
Make sure the panel and the surrounding area is clean.
Applying the Paint Protection Film
Wash your hands and make sure they are absolutely clean.
Apply the PPF out of direct sunlight and in an area free of dust and wind.
Air temperature should be between 55 and 90 degrees.
Spray a mist of slip solution onto the panel where the PPF will be installed and at the
same time spray your fingers so that there is no chance of making fingerprints on the
PPF.
Peel back the PPF from the backing sheet and spray both sides with the slip solution.
Lay the film onto the panel and slide into position.
For the fender stone guard, I find that it works best to generally work the film downward
rather than upward. So, peel back the top portion of the stone guard taking care
not to move the guard out of position and spray the panel and back of the PPF with
the alcohol solution. Then lay back into position and squeegee the top portion out.
This will tack the film into position. The alcohol solution acts to speed the adhesive process.
Now use the squeegee to work the bubbles and slip solution out from under the PPF by
generally moving in a downward and outward direction. Hold the squeegee at an angle
of about 45-60 degrees to the panel. Applying moderate pressure, push or pull the excess
solution from under the film towards the nearest edge.
If necessary wet the topside with slip solution to ease the squeegee action. (But avoid
using excess solution as this creates surface bubbles and may hide underlying solution
bubbles)
Seal and dry the film edges using the plastic hard card wrapped in a paper towel.
You can also use a little steam pressure on the edges followed by the hard card and
paper towel to lock down the edge and dry it.
Once the install is complete, spray a light mist of slip solution over the surface area
and wipe clean with a paper towel.
Wait 2 days before washing the panel with the PPF so that the adhesion process can cure.
Afterwards wax the PPF with a non-pigmented wax.
Problems and What To Do
What could go wrong?
Paint peeled off with the old stone guard
Assuming that you used plenty of steam and pulled the plastic at a 90 degree angle
to the panel, if paint peels off then it is because the paint was not bonded good to the
surface of the panel. Generally you need to wait 30 days after a fresh paint job. It may
be possible for the paint to be cured before that, the painter's should be able to tell you.
Your only option now is to repaint and make sure it is cured before applying the PPF.
Bubbles in the newly applied stone guard
If during installation and before adhesion has taken place, you can lift the PPF and
rework the film with the squeegee to remove bubbles.
If you notice bubbles after the installation, there are 3 options. First is to wait 2 weeks
to see if the bubbles dry up and disappear. The second is to use a insulin syringe
to relieve the air and solution under the film. To do this, bend the needle at a 45 degree
angle and insert into the base of the bubble. If the bubble is filled with solution, extract
the solution using the syringe. If the bubble is filled with air, inject alcohol solution
into the bubble and expand the bubble just a bit and then extract the solution. The third
solution is to replace the PPF this time being more careful about getting the air and
bubbles out.
I'm not a fan of popping the bubbles. I would rather remove the film and start over.
With items as small as these stone guards it is a simple matter to lift them and start
over.
Caring for Paint Protection Film
Just a few notes about caring for the PPF.
Wait 2 days after installing before washing the panel.
Do not buff the PPF with abrasive cleaners or polishes (such as the #80 Speed Glaze).
Wax the PPF using a non-pigmented wax, such as Meguiar's Tech Wax 2.0
Cost Comparisons - Custom vs Porsche vs 3rd Party
Porsche painted 12 stone guards are about $83 each.
Porsche clear 12 mil stone guards are about $60 each.
Third-Party clear 12 mil stone guards are about $45 each.
The custom 8 mil 3M VentureShield fender stone guards are about $25 each
and
the custom bumper stone guards are about $7 each.
This DIY was written from my own experience and includes some product and application
information that was provided by 3M.
If you would like to use my patterns, go to this link and download the files:
https://drive.google.com/folderview?...0E&usp=sharing
The Adobe Illustrator files (.ai) are about 12MB each and the encapsulated
postscript files (.eps) are about the same. Site restrictions make these files
too big to upload as an attachment to this DIY.
-bruce
In this DIY I will show how I made some custom stone guards for my 1997 Porsche 993.
First, the backstory. I had some body work done on my car which resulted in the
left side being repainted, including the rear bumper cover. This necessitated replacing
the left side stone guard which was the Arctic Silver painted style. The old guards were
quite beat up, so I was looking forward to refreshing them. With 15 years of rock hits,
there were lots of little black specks in the painted top coat. The new guards were an
instant improvement, but upon closer inspection, there were white blotches under both
guards which appeared to be manufacturing defects. But of a more serious note was
the fact that the body shop didn't quite get the curvature of the rear fender right at the
bumper cover line so it was sent back for a redo.
This time they got the curve right, but now Porsche had run out of stock on the painted
guards and had decided to obsolete them. OK, I had been thinking that maybe the clear
guards would be a better idea in the long run anyway. So we order up a set. The first
set had one that was damaged so it was reordered. It came in damaged so another
one was ordered. Eventually we got a set without imperfections and they were installed.
But, the installer managed to tilt the one on the left side and not get it on
straight.
But there's more. The rear bumper cover was repainted and the years of road rash
behind the wheel on the leading edge of the bumper cover was corrected with new paint.
So I thought now would be a good time to protect this edge with paint protection
film (PPF). I found a shop that installed PPF and asked them to install some protection
for this edge. They suggested I use a pattern from their catalog for low cost. I said OK.
But I later found out that it did not cover the entire exposed area behind the wheel.
So, I located another shop and explained I wanted to have complete coverage behind
the wheel so there would be no road rash. He said he had 5 catalogs of patterns but
none of them provided complete coverage. He attempted a custom replacement of
what I had, but in the end did an incompetent job on one side where he goofed the curvature.
Fed up with all this, I decided to learn how to make stone guards and install them myself.
Overview of the Process
Photos that illustrate this DIY can be found here:
https://picasaweb.google.com/bruce.c...r75fvCt_TQ4AE#
I only wish I had 3 hands or an assistant to get more photos to document the process better.
The process to create a stone guard is only a few straight-forward steps.
- Create a stone guard pattern in Adobe Illustrator and output a vector file (*.eps).
- Take the vector file to a Graphtec cutting plotter
- Choose the PPF stock and cut the pattern out
- Install the PPF
The rest of this DIY will discuss each of these steps.
Tools Needed
Steam canister, e.g. McCulloch MC1275
2 spray bottles
4 inch rubber squeegee
plastic hard card
Dual-Action polisher and a light abrasive polisher such as #80 Speed Glaze
To create patterns you will need Adobe Illustrator and a scanner.
Materials Needed
New stone guards
Johnson & Johnson Baby Shampoo
70% Isopropyl Alcohol
distilled water
microfiber towels
paper towels
3M general purpose adhesive remover
Making the Fender Stone Guard Pattern
I took one of the original Porsche stone guards before installation and scanned it
at 100% on a Xerox machine. Because the stone guard was too large to scan all at
once, I made two alignment marks with a pen. Then I scanned the top half and bottom
half separately. The Xerox will output a .jpg file of the scan.
The two .jpg files were then brought into Adobe illustrator and merged using the
alignment marks. Next I traced the outline and then output a vector file.
You only need to do this for one side as the other side can be easily mirrored in Adobe
Illustrator.
Making the Bumper Stone Guard Pattern
To make the bumper stone guard pattern, I used a tape mask technique. Using blue
painters tape, I taped the area I wanted to cover with PPF. I laid down 2-3 layers of
tape being careful to make good clean edges. I then lifted the entire tape mask off
and placed it onto a piece of paper.
The tape mask was then scanned in whole on the Xerox machine. Then, as before,
the .jpg file was brought into Adobe Illustrator, traced and a vector output file created.
Selecting the Paint Protection Film and Getting the Patterns Cut
One of the advantages of this process is that you can choose from a number of PPF
products to make the stone guard from. I talked with Dean at Sticker City in Van Nuys,
about my options and chose 3M VentureShield which is 8 mil PPF.
Aware that Porsche specified 12 mil PPF, I was initially concerned whether or not 8 mil
would be sufficient. I'm pretty much convinced that it is and if it weren't, you can bet a
business like Sticker City would not be using it. But just to test the idea myself, I decided
to leave the Porsche 12 mil stone guard on the right side alone and that way after a
year or so I can compare.
Visually the 8 mil VentureShield is a little less obvious than the 12 mil Porsche guard.
By the way, did you know that in the five catalogs I mentioned earlier that not one
of them has an exact match for the Porsche fender stone guard? Yet another reason for
going this route.
Having chosen the PPF stock, I handed my patterns over to Dean via my Porsche
USB drive. He set up the Graphtec plotter and cut-out the stone guards, providing me
my new guards all rolled up and packaged in a sealed plastic bag.
Now, you want to be careful not to damage the guards before installing them.
Don't be like Porsche and crease the guard or damage it in some way.
Removing the Old Stone Guards
Steam is your friend. I used a McCulloch MC1275 steam canister to remove the old
stone guards. These tools are about $125 and can do a lot more than just remove old
stone guards. They can be used for car detailing and they can be used for installing
PPF as well as removing PPF. They also have other uses around the house.
Use lots of steam. Lift up a corner of the film with a fingernail and pull the film off the
car at a 90 degree angle. Don't go too fast, be sure to apply lots of steam to soften and
loosen the film before pulling on it.
If you encounter peeling paint with the removal, see the section below on problems
and what to do. It is not normal to have paint peel off with the PPF.
After the PPF is removed, clean the surface of the panel to remove old glue residue
and wax. 3M General Purpose Adhesive Remover generally works well enough. Some tough
glues may need gasoline to help soften and remove. Afterwards, use a dual-action
polisher to polish the surface of the clear coat and wipe down. I like Meguiar's
products
and used #80 Speed Glaze on a yellow pad with a Meguiar's DA polisher.
Preparing to Install
You are going to need two solutions to apply the new PPF.
Slip Solution
Fill spray bottle with distilled water. Add 6 drops of Johnson & Johnson Baby Shampoo.
Shake to mix the solution.
Alcohol Solution
Fill spray bottle halfway with 70% Isopropyl alcohol. Fill the remaining half with
distilled water. Shake to mix.
Squeegee
Before the first time the rubber squeegee is used it should be boiled in water
for 1 minute to help soften it. It must be soft not hard or it will mark the film.
Make sure the panel and the surrounding area is clean.
Applying the Paint Protection Film
Wash your hands and make sure they are absolutely clean.
Apply the PPF out of direct sunlight and in an area free of dust and wind.
Air temperature should be between 55 and 90 degrees.
Spray a mist of slip solution onto the panel where the PPF will be installed and at the
same time spray your fingers so that there is no chance of making fingerprints on the
PPF.
Peel back the PPF from the backing sheet and spray both sides with the slip solution.
Lay the film onto the panel and slide into position.
For the fender stone guard, I find that it works best to generally work the film downward
rather than upward. So, peel back the top portion of the stone guard taking care
not to move the guard out of position and spray the panel and back of the PPF with
the alcohol solution. Then lay back into position and squeegee the top portion out.
This will tack the film into position. The alcohol solution acts to speed the adhesive process.
Now use the squeegee to work the bubbles and slip solution out from under the PPF by
generally moving in a downward and outward direction. Hold the squeegee at an angle
of about 45-60 degrees to the panel. Applying moderate pressure, push or pull the excess
solution from under the film towards the nearest edge.
If necessary wet the topside with slip solution to ease the squeegee action. (But avoid
using excess solution as this creates surface bubbles and may hide underlying solution
bubbles)
Seal and dry the film edges using the plastic hard card wrapped in a paper towel.
You can also use a little steam pressure on the edges followed by the hard card and
paper towel to lock down the edge and dry it.
Once the install is complete, spray a light mist of slip solution over the surface area
and wipe clean with a paper towel.
Wait 2 days before washing the panel with the PPF so that the adhesion process can cure.
Afterwards wax the PPF with a non-pigmented wax.
Problems and What To Do
What could go wrong?
Paint peeled off with the old stone guard
Assuming that you used plenty of steam and pulled the plastic at a 90 degree angle
to the panel, if paint peels off then it is because the paint was not bonded good to the
surface of the panel. Generally you need to wait 30 days after a fresh paint job. It may
be possible for the paint to be cured before that, the painter's should be able to tell you.
Your only option now is to repaint and make sure it is cured before applying the PPF.
Bubbles in the newly applied stone guard
If during installation and before adhesion has taken place, you can lift the PPF and
rework the film with the squeegee to remove bubbles.
If you notice bubbles after the installation, there are 3 options. First is to wait 2 weeks
to see if the bubbles dry up and disappear. The second is to use a insulin syringe
to relieve the air and solution under the film. To do this, bend the needle at a 45 degree
angle and insert into the base of the bubble. If the bubble is filled with solution, extract
the solution using the syringe. If the bubble is filled with air, inject alcohol solution
into the bubble and expand the bubble just a bit and then extract the solution. The third
solution is to replace the PPF this time being more careful about getting the air and
bubbles out.
I'm not a fan of popping the bubbles. I would rather remove the film and start over.
With items as small as these stone guards it is a simple matter to lift them and start
over.
Caring for Paint Protection Film
Just a few notes about caring for the PPF.
Wait 2 days after installing before washing the panel.
Do not buff the PPF with abrasive cleaners or polishes (such as the #80 Speed Glaze).
Wax the PPF using a non-pigmented wax, such as Meguiar's Tech Wax 2.0
Cost Comparisons - Custom vs Porsche vs 3rd Party
Porsche painted 12 stone guards are about $83 each.
Porsche clear 12 mil stone guards are about $60 each.
Third-Party clear 12 mil stone guards are about $45 each.
The custom 8 mil 3M VentureShield fender stone guards are about $25 each
and
the custom bumper stone guards are about $7 each.
This DIY was written from my own experience and includes some product and application
information that was provided by 3M.
If you would like to use my patterns, go to this link and download the files:
https://drive.google.com/folderview?...0E&usp=sharing
The Adobe Illustrator files (.ai) are about 12MB each and the encapsulated
postscript files (.eps) are about the same. Site restrictions make these files
too big to upload as an attachment to this DIY.
-bruce
Last edited by bruce7; 04-22-2013 at 08:05 PM. Reason: edited link to download stone guard files
04-15-2013, 02:41 PM
#3
Racer
Thread Starter
Updated with download link to stone guard patterns
I updated the original post with a link to download the stone guard files.
The link is at the end of the post.
First time I've used this (Google Drive) so interested to see how it works out.
-bruce
The link is at the end of the post.
First time I've used this (Google Drive) so interested to see how it works out.
-bruce
04-22-2013, 03:05 PM
#4
Thanks for the awesome write-up. I tried the downlink link, but it's not working for me. Not sure why...might be an issue on my end. Anyone else get it to work?
Thanks!
Thanks!
04-22-2013, 03:24 PM
#6
Rennlist Member
excellent write up Bruce
04-22-2013, 03:39 PM
#7
Thank you for taking the time Bruce. You are a real asset to the community and conclusive proof that in matter of posts number quality matters. Very helpful.
Trending Topics
04-22-2013, 07:17 PM
#11
Racer
Thread Starter
Link problem solved
OK, the permissions problem was solved with Google Drive and you can
now download the files. The original link in the first post was revised
and should work now.
-bruce
now download the files. The original link in the first post was revised
and should work now.
-bruce
04-06-2016, 03:21 PM
#13
Racer
Thread Starter
Updated with new link to photo album
Here is the new link from Google:
https://goo.gl/photos/BhZzCwDcitC1FyUz6
-bruce7
P.S. Just wanted to give a shout out to Eric Budnick, owner
of Dirty Devil Customs. I took my patterns to him and he just
cut out and applied the bumper stone guards with a
perfect fit following a recent bumper respray.
He is in the San Fernando Valley of L.A. and can
be reached at 818-290-3300 if you need clear bra application.
https://goo.gl/photos/BhZzCwDcitC1FyUz6
-bruce7
P.S. Just wanted to give a shout out to Eric Budnick, owner
of Dirty Devil Customs. I took my patterns to him and he just
cut out and applied the bumper stone guards with a
perfect fit following a recent bumper respray.
He is in the San Fernando Valley of L.A. and can
be reached at 818-290-3300 if you need clear bra application.
05-26-2016, 07:26 AM
#14
Instructor
Thanks for putting in the effort and sharing the files. 
05-26-2016, 06:03 PM
#15
RL Community Team
Rennlist Member
Rennlist Member
Interesting. I purchased a $6 roll of stone guard, traced the area I wanted to cover on tracing paper. Laid it out on a table to smooth the lines, taped it to the plastic guard sheet and cut it with a scissors. Applied with a little dish soap, done. The hardest part was removing the old guards. Used a $18 hand clothing steamer and a non-marring plastic chisel /scraper from Harbor Freight. Don't fret any loss of symmetry from left to right or variability in the rounds in the corners as any variance basically becomes invisible once the guard is applied.
