Block Sanding Primer Do’s and Don’ts


100 Comments

  1. Patty Sherwood March 1, 2015 at 10:48 pm

    I watch my son do this. Now I understand more from your video. I want to help restore a Bertone X 1/9 . Tomorrow, I sand the hood he primed Saturday…carefully. Thank you for explaining so much. We did a VW Bug last month. Beautiful. Learning auto body work is so fun, I barely cook anymore. We have nice cars but we are hungry.

  2. RUSHNBOBO March 5, 2015 at 9:19 pm

    Starting with 320 grit ensures that the paper will roll into and over imperfections.  
    START WITH COURSE PAPER  80-150.  Course paper properly cuts the highs and levels to the lows.  Too fine a paper (even with a block) will often roll over the imperfection.

  3. David S April 1, 2015 at 8:10 am

    If you have a low spot after the guide, can you add a skim coat of body filler on top of primer?

  4. Dalerick Wesley April 28, 2015 at 1:40 am

    will aerosol  primer work as well as

  5. allstetic Netic May 2, 2015 at 1:43 am

    i learned alot thax

  6. John May 19, 2015 at 8:05 pm

    So When i spray my epoxy primer, i let it dry than i proceed to spray primer surfacer than i let it also dry. So right from the beginning do i put on guide coat and sand with 220, or do i sand first than apply guide coat over what i just sanded?. I'm confused of the order in which i lay down guide coat  and sand.

  7. James Howard July 27, 2015 at 11:31 pm

    Hi so you sand your primer with 320 then 500.  When I sand with 320, the 320 removes the primer, so I would have to spray it with primer again to sand with 500?

  8. James Howard July 27, 2015 at 11:34 pm

    I just bought new panels for my 95 Ford F350.  The panels have black primer on them.  I am told I have to fully remove the cheap primer and apply primer again before painting.  Is this true or can I just sand with 320, splash some Johndeer primer on it then sand it with 500 and apply one or two coats of my single stage paint?

  9. James Howard July 29, 2015 at 10:44 pm

    Thank you for the quick reply!

  10. grant domigan September 13, 2015 at 8:38 pm

    If a low spot is found after blocking does the guide coat need to be removed prior to building up the low spot?

  11. Brian Young September 23, 2015 at 4:06 pm

    after sanding with 320 and all is straight, should I guide coat again and finish with 500grit?

  12. Jim Croyle October 3, 2015 at 2:52 pm

    Thanks for the information

  13. Peter Elios October 22, 2015 at 3:16 pm

    Outstanding videos, excellent presentation.

  14. paul snr occ choppers October 29, 2015 at 12:48 pm

    Awsome thankyou im in australia im moulding monaro bonnet scoop in and found your video very helpful i dont have any skills in body or paint work and have no help the people i no with experience back yard painters seem to no alot about nothing you have sumed the guide coat up for me as i couldn't work out the purpose of sandind every bit of black paint off and still be left with low points with no paint thanks your presentation is clear helpful and detailed keep up the good work

  15. Amir Eghbal November 9, 2015 at 10:21 pm

    Can you prime over the low spots of guide coat? If you hit metal and you don't want to sand the low pots (which makes sense) what are you supposed to do? Either needs to be cleaned off or primed again over. I use 3m dry guide coat, I tried washing it with soup and water, tried rubbing alcohol, it didn't work.

  16. buford t. justice November 13, 2015 at 12:45 pm

    Good information!

  17. Alfie Beard January 1, 2016 at 6:00 pm

    Excellent and very informative thank you.

  18. Alex Tsakopoulos January 2, 2016 at 8:33 am

    Amazing video. I worked under a professional for a short time years ago and your video reminded me of the things I forgot. Very comprehensive and well made. Thanks for taking the time. Much appreciated.

  19. HeadNtheClouds February 12, 2016 at 1:55 am

    So you can't show us as you're speaking how you do it? I'm trying to figure out if I need an epoxy under the primer & if you shoot primer over the 800 grit sanded spots. Can't seem to feather the paint enough not to see a line !

  20. DEBOSS GARAGE February 24, 2016 at 11:34 pm

    awesome drinking game. Take a swig everytime he says "block"

  21. S Aman February 26, 2016 at 12:51 am

    awesome video thanks .

  22. Casey Fuler March 14, 2016 at 8:57 am

    Sweeet

  23. Michael Hinchey March 23, 2016 at 11:37 am

    What are your tips on putting glaze over primer? Steps starting from what sand paper to reprep for the glaze?

  24. Rick Trojacek March 27, 2016 at 4:02 pm

    Thank you for the good video. Restoring my 1971 Lemans Sport convertible, and just cannot afford to pay the 10-15 grand I've been quoted by several for a good street paint presentation. Most shops seem to think concours or nothing. I found a mobile soda blasting company that will do soda blast at my garage. The car is relatively clean of rust with some typical body dings and some wavy panels. I figure if I can do the bodywork and prep, I can save a bundle to then have it professionally painted. Again, thank you.

  25. Joe Flash April 20, 2016 at 4:24 pm

    I am painting my 91 Cadillac Brougham. I am using slick sand feather fill g2. When I block sand the panels. I keep sanding thru a few edges to metal. I have an epoxy primer under it. I have two coats of epoxy and two coats of feather fill. Do I need more coats of feather fill to avoid this? Maybe tape the edges? Thanks.

  26. Jay Robertson May 1, 2016 at 7:13 am

    great video,very informative,especially (long block)

  27. flowman777 May 2, 2016 at 9:20 pm

    How about 180 then 320  then made 500…?

  28. JosephDR May 7, 2016 at 11:42 am

    Thanks for the great tips! Very helpful!

  29. jlp613 May 17, 2016 at 4:59 am

    do you ever fill low spots with filler or glazing putty?

  30. Keith Harris June 9, 2016 at 1:22 pm

    thank you. I'm new when it comes to sanding and blocking. Great tutorial now I know what type of block to use in different places

  31. Artur Brzuza July 7, 2016 at 1:04 pm

    FINALLY, an instructional video that explains everything I was wanting to know about prepping, priming, blocking and using guide coat!!! Subscribed and thankyou for also considering the people on a budget! I already threw a lot of money out on the rustoleum paint roller technique only to go back to step one again because I either didn't prep right or because crutial information about prepping were left out. Lots of wasted sandpaper, paint and disappointment. I wont be using a spray gun but the techniques you described will help a lot

  32. Kevin Morgan September 4, 2016 at 5:18 am

    No nonsense video on how to,paint your car properly. The best one on the web.

  33. Robert Nun'ya September 8, 2016 at 1:22 am

    I learned a lot. Thank you

  34. Art Cabral September 19, 2016 at 12:07 am

    Good and informative video.. Well done.

  35. Robert Judkins September 19, 2016 at 1:26 am

    Thank you so much for the tips. I'm restoring a 1959 Glastron Fiberglass boat and just primed the hull and wasn't exactly sure what to do next to prep for the finish coat. This video was exactly what I need to see.

  36. lastchapter September 27, 2016 at 10:33 pm

    I"m a retired Auto Body technician, yes we are Auto Body Technician's not Body Men. Any way this man sure knows his trade. Thanks for the great video….Canada.

  37. 82 GMC Restoration October 14, 2016 at 11:45 pm

    if you block and hit metal,do you re apoxy and surfacer or just surfacer

  38. Harold Lounsbury October 17, 2016 at 1:08 am

    Excellent, final sanding explained.

  39. Scott Levenduski October 29, 2016 at 7:11 pm

    Thank you! Nice video i learned a lot!

  40. Tony Fourpaws December 1, 2016 at 7:17 pm

    Thank you. I have been learning a lot here lately in preparation for my first paint project. I have an extremely amateur question:

    Do blocks wear down easily and should i get more than 1

  41. Joseph Lorentzen January 7, 2017 at 4:40 am

    Thanks. I think I am ready to make my first attempt.

  42. Peter Elios January 7, 2017 at 4:11 pm

    Excellent. Thank you

  43. JDPower 55 January 14, 2017 at 11:10 pm

    Very nice video, thumbs up!

  44. Monte Keppner January 28, 2017 at 5:08 am

    More do less talk please

  45. Spetsnaz Pocomaxa January 30, 2017 at 7:11 am

    I was taught to block primer with 320 grit. If everything is okay, then I would wet sand it by hand with 400 grit and that was the last thing to do as far as sanding goes.

  46. Spetsnaz Pocomaxa January 30, 2017 at 7:16 am

    I wouldn't risk using an air-powered tool like a DA sander to block with. It's too easy to mess something up, like digging into the primer, and just overall ruining whatever you primed. I tried to "block" using a DA sander once, and yeah, I screwed my hood up!!!! So I had to basically do everything all over again. DO ALL BLOCKING BY HAND! Just my very honest opinion.

  47. David Day February 15, 2017 at 11:51 pm

    If you used contrasting color primers couldn't you use sandable primer?

  48. Eazy E February 16, 2017 at 4:47 am

    So, I guess you can't block sand epoxy primer then? Is it only possible to block sand polyester primer surfacer or 2k urethane primer surfacer?

  49. Stephen Garrett March 2, 2017 at 11:01 am

    Block sanding by hand is the way to go, I agree. Do you re apply guide coat in between 220 and 320 stages?

  50. Heno Reno March 9, 2017 at 11:25 pm

    very nice videos ,thanks

  51. mark race March 26, 2017 at 2:36 am

    great series by a real professional, keep up the good work, I have not only learned a lot but also refreshed my memory on a couple of basic methods

  52. Space Warrior June 11, 2017 at 2:31 am

    Daym dude your really good!
    Ericthecarguy sent me here.

  53. mattie amos June 11, 2017 at 4:06 am

    Makes a lot more sense now thank you

  54. wildeyednorthernboy June 18, 2017 at 1:53 pm

    all u really do is talk about it…i didnt c u sand anything yourself TRUE

  55. tertessa June 22, 2017 at 2:12 am

    great info.. thanks

  56. Macaroni Jack July 11, 2017 at 7:48 pm

    black lacquer primer

  57. Ronald Guerra July 16, 2017 at 3:08 pm

    How can I get the product needed for body work in my country Trinidad and Tobago..

  58. Mike Daran July 19, 2017 at 7:47 pm

    u r a wonderful teacher really

  59. ozmaniac49 July 30, 2017 at 1:09 pm

    Great tutorial, thanks a lot mate.

  60. Donovan Miller August 21, 2017 at 2:20 pm

    tip. mask off Butler where's the violin instrumental in the back?

  61. Kristyn Leamon August 29, 2017 at 11:26 pm

    You packed a lot of good useful info into this video. Thanks for taking the time to film it!!

  62. charlie johnson November 1, 2017 at 11:15 am

    Outstanding. To say the least… Im going to use his methods . like NOW… Yes ive tipped the block.. Yes i used tbe walmart paint. . ive done the dont's… It is now time for the do it correctly. Tnsbk you

  63. Cassiel Ligthman December 9, 2017 at 6:38 am

    Your video is great just could be awesome if you show on video what you explain.

  64. Stefan Kokal December 16, 2017 at 11:29 pm

    Bla bla bla bla

  65. Frank Valencia December 24, 2017 at 1:08 am

    Great tips and techniques my man!!!..awesome job on the video!!

    👍🏻👍🏻

  66. Dylan Bradford December 27, 2017 at 7:26 am

    Tips was a lot of help was unsure what to do when coming to bare metal when block sanding it 16 restoring a 65 mustang 289 4 speed k code car

  67. fwh79 January 9, 2018 at 12:05 am

    This video is incomplete because you do not show how to check your work using a solvent cleaner. Which seems like it is the most important step and also the real answer to "When do I stop?". Also, the example of a feather edge at 8:16 is terrible. That is not a feather edge… that is an edge map waiting to happen. If you primer a feather edge in that condition, you will be applying a second round of primer to the repair area guaranteed. Here is some thing else for the MSO techs who are comission paid book time out there: What are you getting paid for block sand and prime??? I almost never got time on my sheet for block sand and prime. Which is funny because the insurance companies are pushing HARD for repairs over placement parts. So, as a refinisher, I am literally working for free every time I prime and block sand a repair panel. Or I am paying for a prepper that is block sanding and priming cars for free… still costing me (us) money either way. But there is more…. I am also missing the repair TIME for the block sand and prime operation. So lets look at EVERYTHING this missing TIME effects… 1. Missing time means I am missing pay on my pay check. (That's ok, I should enjoy working for free???) 2. Missing time means the vehicle has less time allocated to cycle time. 3. Missing time means, time missing on the sheet that pays for MATERIALS. I wonder if any of the refinishers reading this have ever heard the following from an owner or management… This car is late (cycle time issue) Customer is paying for a rental (cycle time issure) We need to have a meeting with the paint shop about material costs/usage (missing material costs that should be billed out to the insurance company. This is always funny to me because ME not getting paid is fine… but the SHOP missing money, unacceptable!) Not to mention… what if you have to reprime a car??? You just primed a car twice FOR FREE. And consumed DOUBLE the material… gee, I wonder why material costs are so high??? Oh yeah, and you got paid even less because block sand and prime was not a line on your sheet in the first place. So you primed and blocked a car twice for FREE. It is actually worst than free, because you missed out doing a repair procedure you actually get paid for. But hey… the insurance company saved money! Ever wonder why the body men make way more money than you do? (Cause you are fixing their terrible body work at YOUR own expense while they are working on their next car.) Don't you love how the body men work less hours than you and still make more money? That's ok… just keep working for free. And hey, can you come in early tomorrow? Or stay late? We need to get these cars done. And THE BEST LINE EVER said to me… Hey bro, you can "make it up in volume" … REALLY??? HOW??? Every car is missing time. You can't make it up! And further more, why am I "making it up" it shouldn't be missing in the first place! Body men should block sand and prime their own repairs… PERIOD. They should be held accountable for their repairs. Do body men match color for me??? No, that's my job. I wouldn't expect them to do that. So why is the paint shop expected to finish a body mans job for him? You techs should stop and think about how much time a week goes into block sand and prime. You are being scammed, badly! I know that not all shops are like this. I am sure some shops get time for block sand and prime. However, all the shops I have worked for over 20 years now, do not get block sand and prime time. What do you commission techs think about that? Do I have a point? Do any of you have a story you would like to share with us? Is this only happening to me?

  68. Craig Maggi January 15, 2018 at 6:57 pm

    Your video was very helpful,thanks

  69. victor gamez March 3, 2018 at 6:32 am

    Thanks for taking the time to teach and share your knowledge

  70. Alfredo Luciano March 11, 2018 at 1:52 am

    Great video I love the way you explain things simply and down to earth big 👍 and subscribed

  71. Chris Hale March 29, 2018 at 7:52 pm

    Great video. Just found you on YouTube. Great teacher. I’m a subscriber

  72. DaySurge April 5, 2018 at 3:55 pm

    I certainly learned a lot. Thank you for a great presentation.

  73. Jack Davis April 16, 2018 at 9:17 pm

    Great video, thanks for making it

  74. david smith June 16, 2018 at 12:42 pm

    As I have had some previous diy experience with bodywork and spraypainting your tips an advice have worked for me,the guide coat bit definitely worked on my m/cycle fuel tank,and the end result was better than all my previous diy work,true,proper prep is required for good end result,kind regards.

  75. The Captain June 25, 2018 at 12:51 pm

    Who's playing harry potter in the background on a single string? xD

  76. Luis Carrion July 5, 2018 at 4:43 pm

    Thank you

  77. ACLTony July 5, 2018 at 8:49 pm

    Donnie, very well presented!

  78. Richard Lane July 17, 2018 at 12:05 pm

    what do i do when block sanding the high build primer and sand to bare metal

  79. mike mikesbbody August 15, 2018 at 6:16 am

    Awesome video! great help Donnie! Mike… New Zealand.

  80. Ron Jasper August 17, 2018 at 1:27 am

    Great job

  81. Randy Pullman October 7, 2018 at 5:09 pm

    Any pointers on painting motorcycle tanks from the 70s and their fiberglass bits?

  82. tertessa October 19, 2018 at 1:56 am

    Thanks for the class…. I'm right into block sanding now.

  83. ajuk1 November 25, 2018 at 10:56 pm

    Apostrophe fail.

  84. Fred Jones December 19, 2018 at 2:44 pm

    Question, what’s the best action to take if I didn’t block the primer enough, I put a base coat, now the primer is raised through the base coat. What’s the best grit of sand paper to fix this, and do I wet sand or dry sand??? This my first time doing this

  85. BRKK47 January 16, 2019 at 1:36 am

    I like videos like this… But I get distracted by his hair… Just rock the receding hair line.

  86. crazyraptor January 24, 2019 at 7:50 am

    do we guide coat everytime we change grid?

  87. Gary Lamb February 17, 2019 at 2:10 am

    How many of you wanted him say get er done?

  88. 34 SV March 30, 2019 at 3:48 pm

    Tremendo video. Gracias!

  89. Alexis Pedroso April 18, 2019 at 7:20 pm

    I`ts very pleasant watch the masters of the trade share the right knowledge"

  90. Curt Brennan May 3, 2019 at 2:09 pm

    I've been an autobody hobbyist and have run a small shop since the mid '70s and it's good to see some of the tips you have here. It's always good to learn new things. Thanks for posting!

  91. aaron anderson May 5, 2019 at 7:28 am

    I have never had cheap flat black spray paint to gum up, ever! Used it for 15+ years.

  92. Andrew Hurlock May 8, 2019 at 4:27 pm

    Instead of guidecoat, use ink if you're trying to be cheap. But not spray paint.

  93. Juan Cebolla June 12, 2019 at 1:24 am

    Thanks 4 that hint
    😊 Donny know I can eat a donut 🍩😂😂

  94. Sponge Bob June 14, 2019 at 9:11 pm

    I love your fringe.

  95. Cory Soura June 26, 2019 at 10:24 pm

    Nice analogy about the boat and the waves, great job keep it up

  96. Emoke Karacsonyi July 20, 2019 at 1:43 pm

    Thanks very helpful and hope to be trying is soon. Also a delight to watch such a video without the bad language

  97. arman siddiqui July 20, 2019 at 5:54 pm

    Nice jobs

  98. troy yamaguchi July 30, 2019 at 3:02 am

    ALL THE GLORY HONOR PRAISES MY WORSHIP TO JESUS THE SON OF GOD MY GREAT AWESOME SAVIOR JESUS PROVIDER PRECIOUS BLOOD JESUS LAMB PRECIOUS PRESENCE PRECIOUS FIRE HOLY SPIRIT POWER LIVING WORD OF THE LORD JESUS, WISDOM AUTO BODY PAINT

  99. Lori Rester August 28, 2019 at 1:10 am

    I thought you shouldn't sand epoxy primer.

  100. Dee daartyst October 4, 2019 at 3:31 pm

    Thaaaank youuuuuuuu, very very informative, will do, and im off & running.

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