ALL: Minor DIY Patch/ReSpray

[audisnapr]

Since I've done this a few times now, I figured it's time to share what I've learned… plus I've been hit up a few times to write this DIY'r, so here goes.

This will be PART I of the DIY'r. I will follow up shortly with the rest including photos. Just wanted to get this part out of the way since ppl are asking.

Keep in mind, this type of DIY'r is not black and white, it will take some patients along with trial and error. And remember, don't panic, if you screw up, the worst that can happen is you have to redo it - it may cost you some more time and paint, but with paint, nothing is permanent.

WARNING: I do not recommend first timers of this type of DIY'r to try this on anything other than bumpers and valences - re-spraying door panels, hoods, fenders, etc takes a lot of practice and should NOT be attempted unless you feel super confident.

ITEMS NEEDED:
- 100 grit wet/dry sand paper
- 300 grit wet/dry sand paper
- 600 grit wet/dry sand paper
- 2000 grit wet/dry sand paper

(you can buy the larger sheets and cut them to size or buy the smaller stuff already pre-cut to fit the sanding blocks I will list below - I found that buying the bigger sheets gives you more for your money and you can always save the left overs for a future mod)

- Sponge sanding block
- Hard rubber sanding block

- Blue painter's tape
- Masking paper (can be any kind of paper, but the brown paper rolls you get from Home Depot in the painter's section seem to be cheep and work super well)

- Depending on the task at hand, you may need some sort of body filler to fill in holes or deep scratches on the item that you are painting. For items that are flexible such as bumpers and valences, bondo makes a two-part filler that when dry, stays somewhat flexible. For items that are hard and rigid, you can use any type of body filler that you are comfortable with.

- Plastic spreaders

- Rubbing compound
- Wax
- Applicator pads
- soft towels/cloths (for wax and compound removal)
- Some sort of power tool to apply wax/rubbing compound. You can use good'ol elbow grease, but I find that a cordless drill and a applicator pad attachment saves a lot of time and energy and the results are much more apparent.

- Applicator pad attachment

- bucket (for clean water and for soapy water)
- sponge (to wash items being painted
- towel (to dry off washed items)

- Primer paint
- Base coat paint
- Clear coat paint
- Adhesive Promoter (if painting something plastic/rubber)

[audisnapr]

Now is where the explanation will get a little complicated. For this DIY'r I will assume we are touching up a bumper cover in order to keep things straight forward. Other re-spray jobs will be similar, but for description sake, we'll focus on the bumper.

For small to medium touch-ups, it's not necessary to remove the bumper. If you are re-spraying the entire bumper I would recommend removing it completely, but again not absolutely necessary.

:: STEP 1 ::
Determine the area to be repaired. Using your sponge sanding block or hard plastic sanding block (either is fine) and 100 grit wet/dry sandpaper with water, remove existing paint as necessary. Be sure to be generous with the water regularly. It is not important to sand all the way down to the plastic or even the existing primer. It is however important to at least block down (sand down) the existing paint to remove any gouges or deep scrapes so that the area to be repaired is smooth - make sure the high spots, ie: protruding plastic from gouges, have been taken down completely. Generally you want to sand beyond the damaged area 1-3 inches depend on how deep the scratches are. Once the area in question has been smoothed out sufficiently, move on to step two.

:: STEP 2 ::
NOTE: If you are not contending with deep gouges/scrapes, you may be able to skip this step, but read through just the same.

Since we are talking about a bumper repair here, it is best that you use something similar to bondo's bumper repair kit to fill in any holes or deep gouges. Once dry it remains somewhat flexible and won't crack as easily as the standard body filler.

Wash application area with soap and water, then dry completely.

Mix the two part body filler per the instruction on the product. Obviously you'll have to figure out on your own how much to mix for your specific application. Don't worry about over doing it though. Most of the filler you apply will get sanded down anyway... more in this case is better.

Using the plastic spreaders, apply mixed filler generously to the hole/gouge and the surrounding area about 1" past damaged area. If applying to a hole, it is generally a good idea to epoxy some sort of backer plate to the back side of the bumper to give the filler something to bond up against so that it doesn't just push through. Let filler dry per the instructions. Apply second coat as necessary in time frame per product's instructions.

Once the filler has dried (again, per the product's instructions), using the 100 grit wet/dry sandpaper and the hard plastic sanding block with water, begin to block down the filler. It IS important to take the filler all the way down to the original paint. The filler should only remain in the low areas, ie: gouges/scrapes/holes/dents. Any filler left outside of those areas will show up after the area has been painted. In some cases, it may be necessary to go back and add additional filler after you have sanded down the first filler application. If so, repeat step 2 until you are satisfied with the results.

:: STEP 3 ::
NOTE: Do not skip this step even if you skipped step 2.

Step 3 is where we begin to prepare for paint. Using your 300/320 grit wet/dry sandpaper and sponge sanding block with water (again, be generous with the water), sand application area until smooth. At this point all we are doing is making 300 grit scratches in the paint for the new primer to adhere to, so it is not important to sand hard or for a long period of time. The reason we do not want to skip this step is because 100 grit scratches sometimes can show throw paint. We need to turn those 100 grit scratches into 300 grit scratches.

[audisnapr]

:: Step 4 ::
Wash application area with soap and water, then dry completely. It's a good idea to dry with a lintless towel or at least blow off the area to be spray with canned or compressed air. If using compressed or canned air, be sure not to get any residue from the compressor or canned air on the application area or the paint will not bond correctly. If this does happen, you will need to wash and dry the area again, this time avoiding the compressed air residue.

:: Step 5 ::
A couple things to consider when painting with spray cans.
1. Avoid spraying next to other vehicles or other expensive items!
2. Avoid spraying in areas exposed to a lot of wind. Select a day when the wind is at a minimum or you are in a well ventilated area that is surrounded by structure to block the wind.
3. If possible keep the ground wet with a running hose or re-wet periodically. This will prevent over-spray from sticking to the ground and will wash away easily. Please don't have your parents trying to track me down because you got paint all over the driveway or garage

Be sure to do a good job when masking off the rest of your car. You don't have to mask the entire car when doing small repair jobs. Just be thorough. Use the blue painter's tape and the rolls of brown paper or newspaper to mask off as much as you feel necessary. Remember, you may not be able to see the overspray, but it's there.

The hardest part about masking off the application area is giving yourself enough overspray/blending room. From my experience, your masking job will have to grow as you go from primer to color to clear. For now, mask off the application area giving yourself about 1" past the area in which you sanded. To save yourself some time down the road, instead of laying the tape down flat around the application area which creates a sharp edge, fold the edge of the tape that borders the application area upward. This will help take away the sharp edge and will make it easier to sand away/blend the new paint to the old paint.

Primer is generally a thicker paint than color or clear paint, so make sure to shake the can for a good 2-3 minutes. Walk around and clean up your workspace if you have to while you shake the can. Don't skimp on the shaking.

IT'S ALL IN THE TECHNIQUE!!! Do not hold down the spray nozzle and just keep spraying. The best technique is to do even sweeps from side to side about 8-10" away. Start spraying before the application area and stop spraying after the application area on each sweep. With each sweep across the application area, you should be starting and stopping your spraying. DO NOT HOLD DOWN THE NOZZLE AND JUST KEEP GOING BACK AND FORTH.

Since we are about to paint a bumper which is plastic/fiberglass it is important to prep the area with the adhesive promoter. One light coat followed by one medium coat should be sufficient. Let dry for 15-20 minutes.

PRIMER - FIRST COAT: This coat should be a light coat. Using even sweeps across the application area, apply an even, but LIGHT coat. It does not have to cover completely. You SHOULD be able to see your patch work after the first coat is done. Let dry for 10-15 minutes. The first coat is what gives the remaining coats something to stick to.

PRIMER - SECOND COAT: This coat should be a medium coat. Using the same technique as above in the first coat, apply a medium coat. It may or may not cover completely. It's OK if your patch work still shows through. It should be less visible at this point. However, this is the stage in the game where you will see how good your patch work is. If you are satisfied with the results and don't see any high or low spots, let dry for 10-15 minutes and proceed. If you are unhappy with the results and see high or low spots, let dry for 30-40 minutes and go back to step 2.

PRIMER - THIRD COAT: This coat is the same as the second coat. You can go a little bit heavier, but don't overdue it. You've come this far, you don't want drips and have to go back to Step 3. At this point you should see little to no patch work through the paint. If you do see patch work through the paint, apply a fourth light to medium coat as necessary.

Let final coat dry for 30-40 minutes before moving onto step 6.

:: Step 6 ::
Remove immediate surrounding masking tape and paper.

Using your 300/320 grit wet/dry sandpaper and the hard plastic sanding block with water (remember to be generous with the water), LIGHTLY go over the newly primered area. You are not trying to sand the primer off, you are simply trying to smooth it out and add some scratches for the color coat to adhere to. Make sure to sand/blend the primer to the existing paint - MAKE SURE THE TRANSITION OF PRIMER TO EXIST PAINT IS COMPLETELY SEAMLESS AND DOES NOT HAVE AN EDGE.

Wash application area with soap and water, then dry completely. Be sure to remove all lint and dust before moving on.

:: Step 7 ::
Re-mask the application area. This time, you will move the tape out a little further. The application area should have grown just a bit since you should have been blending the primer to the existing paint. So again, tape off about 1-2" past the primered area using the same folded tape technique as before to help prevent an obvious old paint to new paint edge. MAKE SURE THERE IS AT LEAST 1-2" BETWEEN THE TAPE EDGE AND THE PRIMER.

Wipe off application area one more time to make sure you didn't get any finger oils on the primer.

:: Step 8 ::
Hopefully by now you've nailed your spray technique... it's more important now than ever.

Using your color of choice more or less repeat step 5. Please read through carefully.

SHAKE PAINT CAN WELL BEFORE SPRAYING.

COLOR - FIRST COAT: This coat should be a light coat. Using even sweeps across the application area, apply an even, but LIGHT coat. It does not have to cover completely. You SHOULD be able to see your primer after the first coat is done. Let dry for 10-15 minutes. The first coat is what give the remaining coats something to stick to.

COLOR - SECOND COAT: This coat should be a medium coat. Using the same technique as above in the first coat, apply a medium coat. It may or may not cover completely. It's OK if the primer still shows through. It should be less visible at this point. Let dry for 10-15 minutes.

COLOR - THIRD COAT: This coat is the same as the second coat. You can go a little bit heavier, but don't overdue it. You've come this far, you don't want drips and have to go back to Step 3. At this point you should see little to no primer through the color coat. If you do still see primer through the color coat, apply a fourth light to medium coat as necessary.

Let final color coat dry for at least 1.5-2 hours before moving onto step 9.

:: Step 9 ::
Remove immediate surrounding masking tape and paper.

Using your 300/320 grit wet/dry sandpaper and the hard plastic sanding block with water (remember to be generous with the water), LIGHTLY go over the newly painted area. You are not trying to sand the paint off, you are simply trying to smooth it out and add some scratches for the clear coat to adhere to. Make sure to sand/blend the new paint to the existing paint - MAKE SURE THE TRANSITION OF NEW PAINT TO EXIST PAINT IS COMPLETELY SEAMLESS AND DOES NOT HAVE AN EDGE.

Be careful not too sand too hard or too long in one area or you will go through to the primer at which point you will have to respray the color coat. If you do, don't panic, just go back to step 7, re-wash and re-spray a few more coats.

Wash application area with soap and water, then dry completely. Be sure to remove all lint and dust before moving on.

At this point, the new color paint you just applied SHOULD be dull and flat, don't worry, it's supposed to be like that.

:: Step 10 ::
Re-mask the application area. Like last time, you will move the tape out even further. The application area should have grown just a bit since you should have been blending the new paint to the existing paint. This time, tape off about 3-4" past the new paint area using the same folded tape technique as before to help prevent an obvious old paint to new paint edge. MAKE SURE THERE IS AT LEAST 3-4" BETWEEN THE TAPE EDGE AND THE NEW PAINT.

Wipe off application area one more time to make sure you didn't get any finger oils on the new color coats.

:: Step 11 ::
Clear coat time. Pretty much the exact same as Step 8.

SHAKE PAINT CAN WELL BEFORE SPRAYING.

CLEAR - FIRST COAT: This coat should be a light coat. Using even sweeps across the application area, apply an even, but LIGHT coat. It does not have to cover completely. Let dry for 10-15 minutes.

CLEAR - SECOND COAT: This coat should be a medium coat. Using the same technique as above in the first coat, apply a medium coat. Let dry for 10-15 minutes.

CLEAR - THIRD COAT (ultimately, the number of clear coats is up to you - 3-5 coats should be adequate): This coat should be a medium to heavy coat. This being your final coat of paint, unless you want to do 4 or 5 coats, should be your best coat yet. Be sure to do very even sweeps across the application area. This will be what everyone sees.

Let final clear coat dry for at least 2-3 hours before moving onto step 12.

:: Step 12 ::
At this point you have two choices. If you have done an amazing clear coat job that is smooth and flawless and are satisfied, skip this step and move onto Step 13. If, however, you need to do some blending of the new paint to the old paint, read through this step.

Remove immediate surrounding masking tape and paper. DO NOT REMOVE ALL MASKING JUST YET.

Using your 600 grit wet/dry sandpaper and the hard plastic sanding block with water (remember to be generous with the water), LIGHTLY go over the newly cleared area. You are not trying to sand the paint off, you are simply trying to smooth it out. Make sure to sand/blend the new paint to the existing paint - MAKE SURE THE TRANSITION OF NEW PAINT TO EXIST PAINT IS COMPLETELY SEAMLESS AND DOES NOT HAVE AN EDGE.

Once you are satisfied with the transition from new to old paint and the new paint is perfectly smooth, grab your sanding sponge and 2000 grit wet/dry sandpaper (with LOTS of water) and begin to sand the application area as well as the surrounding areas. Do this gently and lightly. You are trying to remove the 600 grit scratches and replace them with 2000 grit scratches... YOU ARE NOT TRYING TO REMOVE PAINT AT THIS POINT... although you are somewhat.

As you sand, you should not see any colored water. You should see foggy water, which is the clear coat mixed with the water. If you begin to see colored water you have gone through the clear coat and may need to repeat step 11.

At this point, the clear coat you just applied SHOULD be dull and flat, don't worry, it's supposed to be like that.

:: Step 13 ::
If you are completely satisfied with your paint job, go ahead and remove all remaining masking. It's time to polish and wax the new paint.

Most of you know how to polish and wax a car, so I won't go into detail at this stage. If you have any questions/concerns, feel free to PM me.

I will tell you, that the purpose of the polishing compound is to remove the 2000 grit scratches and replace them with polishing compound scratches which is more or less 10,000 grit sandpaper. You may have to do several polishing compound applications to remove the 2000 grit scratches. Using an electrical polishing applicator will make this part of the job MUCH easier as you may need to use the polishing compound for a while. This is the key prep stage to bringing out the shine/luster of the clear/color coat.

The next step is to apply the wax. Again, the purpose of the wax is remove the polishing compound 10,000 grit scratches and replace them with wax scratches (call them 20,000 grit - don't worry, you won't be able to see 20,000 grit scratches). As you do this, you will see that the clear coat will come to life and shine again. You may have to apply several wax coats to get the clear to truly shine and have that luster you imagined. If it does not shine to your satisfaction or match the surround original paint, go back and re-apply the polishing compound a few more times followed by more wax applications. Make sure to go beyond the application area onto the original paint during both polishing compound and wax applications. Be patient and diligent with these applications. Your new paint job will shine once again.