The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Paint & Bodywork

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-02-2017, 09:43 AM   #1
clemsonteg
Registered User
 
Join Date: Jul 2012
Location: Anderson,SC
Posts: 886
Body Filler Application

I am working on the bodywork of my truck during these cold months and this is the first time I am working with body filler. Based on reading here, I decided to go with Rage Gold.

The majority of the body filler I will be using will be going where the upper trim holes used to be. I welded each of the holes and smoothed them over the best I could, so now I would like to apply some body filler and begin making the area appear as if they were never there.

I have 2 questions that I hope will be easy to answer:

The first is, what is the maximum thickness I should do in any single pass with the body filler? Most of the areas are less than 1/8", but I have a few that are slightly over that. Can I apply the filler 1/8" to 3/16" thick in a single pass, sand, and then apply a second coat to any remaining low spots?

Secondly, can I apply the filler to multiple areas now, and then go back later and sand? I am a husband and a dad of 2 small boys, so my garage time is usually limited to an hour or two each night after the little ones are in bed. My plan was to try to get the first coat of filler on both bed sides and both front fenders this week, and then start sanding next week. I wasn't sure if the filler needed to be sanded immediately after it hardens, or if I can wait.

Thanks in advance for your responses!
clemsonteg is offline   Reply With Quote
Old 01-02-2017, 11:15 AM   #2
MARTINSR
Registered User
 
MARTINSR's Avatar
 
Join Date: Dec 2000
Location: San Francisco Bay area Ca USA
Posts: 2,877
Re: Body Filler Application

"Basics of Basics" Plastic filler "bondo"
By Brian Martin

What ever tools you use the trick is to not add the last "skim coat' till you KNOW that it is all you need. Don't try to block out that first coat, just use it as a base for the LAST skim coat.

I was taught this procedure after doing bodywork for a number of years and it really works well:

Just apply a nice coat of filler (what ever brand, whatever style, we will put that aside right now). Cut that coat NOT to make it perfect, but to get the basic shape and filling you need as a base for the skim coat. You can cut it with 36 40 or 80 depending on how big the area you are working is. In other words, if you can cut it fast with only 80 then do it. But I would say that this would be limited to an application that is no larger than about 8 inches.

If you happen to have a few high spots, see if you can tap them down.

If you have a few low spots add a bit more filler to ONLY those spots.

Re-cut these last low spots you have just filled with the same grit you have been using (most likely 36).

If you now have a surface that ONE skim coat will fill, then apply it. If you don't work with it a bit more, but NEVER add a little here or there and think you will finish it without a skim coat.

If you have a surface that is very close with only a few VERY MINOR low spots like poor feathering onto the metal, poor transitions from one application of filler to another, or from the metal that is "poking" up here and there you can do the LAST skim coat.

This skim coat is very important, you want it to extend over the COMPLETE area, this is well past the damage you have been working. Maybe as much as 3 inches past the plastic that you have applied to "rough" it out.

This skim coat can be regular filler or a polyester glaze like "Icing" or "Polyester glazing putty", that is your choice, I use both depending on the size of the area being worked. Do not use anything that doesn’t mix with a hardener. NO, “Spot putty” in a tube, only polyester putties or fillers. If it uses a hardener, it cures to a hard film. The “spot putties” stay soft and can become even softer when the solvent from the primer coats it.

You now run a block, long board, or hog even over this skim coat with a little bit coarser paper than you plan on finishing with to cut off the resin that has surfaced in the filler. I usually just use the 36 or 40 or whatever I have been on the "rough" work. BUT take CAUTION not to cut much off, you want to JUST take the very top, don't really sand AT ALL.

Now finish sanding with your longboard or block or hog or whatever using the finer paper like 80 on a large area or 120 on that small 8" sized area. Block it out to perfection with a nice feather edge to the surrounding metal.

I can't stress enough, the trick is to know when just ONE LAST skim coat will do the job. And apply it COMPLETELY over the surface. If you only one little low spot in the middle, DON'T just do it, skim the ENTIRE thing. You HAVE to have one LAST skim coat over the ENTIRE thing every time. If you get in the habit of this you will do it over and over on every dent you repair and find that you can do just about any dent with just two applications.

As you sand the filler let the board or block you are using run over the surrounding metal. If you only work on the filler you will sand it too low. You need to keep it as high as the surrounding metal, so use the metal as sort of a straight edge that you run the block or board off of.

Don’t worry if you cut through this skim coat here and there. In fact, you WILL most likely cut through. The point of that "LAST SKIM COAT" is that after you add it, you don't add ANY MORE filler. That "LAST SKIM COAT" is just that the LAST filler you add. If you hit a little filler below, or metal, that is normal and fine. The only thing you are looking for at that point is if the panel is FLAT. The filler skim coat is serving no other purpose than to finish you filler work, it is not a "sealer" or anything like that.

You can add fiberglass resin (“A” coat if you have a choice) adding the resin was exactly how I learned from the great Emery Robinson (my personal hero in the auto body world). But remember there was no products like polyester putties back then. When you add resin, that resin comes to the top of the film of filler. It is then something you have to deal with. The whole purpose of the SKIM COAT is to put a layer of filler over the top that is easy to block out with as little effort as possible. You want to be able to concentrate on making the panel FLAT not fighting with gummy resin, sand scratches and the like.

So the polyester putty though expensive is what I use.

How is this for an idea, a co-worker of mine showed me this very obvious tip.

Add pour-able polyester putty to the regular filler! What an idea! LOL A little pour-able squirted into the "bondo" really thins it out nicely.

The "LAST SKIM COAT" should be left to cure a good long time. Where you may jump on filler and sand it as soon as it is hard, the skim coat should be GOOD AND CURED for an hour or more. If you can of course, in the production shop you may not be able to wait that long. The benefits of the procedure will not be diminished.

A little added note, I have found that I don’t use 36 or 40 grit at all anymore. I went to work at a shop that didn’t use the coarser grits so I had to learn not to also. I have found that using just the 80 and then finishing the Skim coat in 120 or 180 works great, even on large panels.

At this shop it was the first time that I wasn’t doing my own primer work. This meant that I couldn’t “cheat” with a lot of primer and blocking the body work “one more time”. I found that I had to get the work PERFECT, then give it to the painter. I did this in an interesting way, I look at the last skim coat as even a more “final” step. I now look it as “primer”. You see I have used polyester primer, which is like spraying “bondo”. They are both polyester resin based and act and sand very much the same. So, I figured why not just “spread out my primer” as the skim coat! It has worked GREAT, the painter jokingly says, “do you think I’ll need to prime this or just paint it?” I tell him, “Just clear it, it’s a shame to hide that work under primer”.

This method has worked great for me, it’s more of a state of mind than a procedure.

And don’t be afraid to buy the best sand paper and use a lot of it, the cost of the paper will be nothing next to the time and muscles saved. Find the paint store in town that services the PROS the Body shops in town, that is were you will get the right stuff and the right info.

****************************************************************************

Additional Info.

Plastic filler refresher.
I thought that a little refresher on the basics of plastic filler was due.
Yesterday I did two small plastic filler jobs that I thought I would share with you. The procedure I lay out in the “Basics of Basics” for plastic filler is pretty clear, I just thought that a couple of real life repairs might be of help. I also wanted to walk through a repair when things didn’t go perfect. How you get out of trouble is almost as important (some will argue more important) than keeping out of trouble to begin with. The first repair was a small 18x12 inch dent in a door of a Hyundai. I don’t think I have to tell you, the metal is very thin on this car which poses unique problems. I have pretty good access from behind with the trim panel removed to push it out. It did need some shrinking (I used my stud welder with a shrinking tip). The metal was pretty close and I figured one filler coat with “regular” filler and a skim coat with polyester putty should be about it. I applied the “regular” filler (in this case Evercoats Rage Gold). I roughed it into shape using my 8” orbital sander with 80 grit. The panel was ready for my skim coat when I realized it had a problem spot. There was a 5” round area that was flexing. This is a common problem with stretched metal. It was straight (or close to it) when “relaxed” but when pressure was applied while sanding it would flex down. So, the pressure flexed it down and sanded it “flat” WHILE it was flexed. The panel then came up to it’s relaxed state and the filler that is on the area would then be high! This is a common problem with beginners, they don’t notice the panel is flexing and block and block and wonder why the panel is not flat.
I had to shrink it in that area so I sanded off the filler in just the effected area and shrank it with the stud gun until the metal was firm. I knew it was not close enough for my skim coat so I applied a thin coat of Rage, just on that one 5” round spot. The rest of the filler stayed as it was, sanded with 80 grit. When I sanded the spot I found that I had not put enough filler on it. There were a few “shiny craters” showing low areas. Now, it was pretty close and a skim coat “may” have taken care of it. But I don’t like “may haves” I like to KNOW when I apply the skim coat THAT is it. I went ahead and applied one more coat of Rage. I sanded it and it was done. NOW at that point I KNEW it was ready for the skim coat. I applied it and it was then sanded to perfection. If I had applied that skim coat too soon and found low spots not filled, I would have had to COMPLETELY skim coat it again, as shown in the next job. It was a mistake, I should have had the metal ready for filler and it would have been done earlier. But such is life. The other repair was on a quarter panel of a 2002 Ford Focus. It was a crease requiring filler in an area about 22x16 inches. As in the “Basics of Basics” you need to give the dent the respect it deserves. The actual damage before the repair was only about 18x6 inches. The paint was stripped out to about 24x18 inches, you need to be sure you are feathering out the filler unto undamaged metal. After pulling the dent (with an Eagle II electric dent puller, neat tool) I applied the filler coat with “regular” filler. I shaped it out rough with 80 grit just getting the body line that ran thru it close. No super detail, I only wanted the line to “be there” and would fine tune it with the skim coat. After applying my skim coat of polyester putty (Evercoat's “Glaze coat”) I blocked it out. I had two areas that were close, but not good enough. One was a tad low, the other had a high spot of metal from the puller poking up. I couldn’t get the high spot to go down with gentle tapping with the body hammer. If I could have done so, and gotten behind the low spot to tap it out I could have saved it. But that was not in the cards. I went ahead and tapped it down with a punch and hammer (to isolate the force) and skim coated the whole thing again. These areas were just four or six square inches in size but I know that feathering a little polyester putty into the surrounding very thin putty would likely be very difficult at best. I skimmed the entire panel. That’s right, the whole thing again. It is a “shell” of polyester putty. Very easy to block, no feather into existing filler. It is just like a primer over the area and much easier to work with. Even though it is more sanding, it is much easier. Again, a mistake necessitated the 2nd skim coat. But mistakes happen and if I would have tried to repair it without another FULL skim coat, it is likely I would have spent even more time to fix it.

Cut your losses and skim it again, but don’t plan on anything less than a skim coat to finish the job.
I want to say there are times when a tiny amount of polyester putty could be applied to pin holes or other VERY tiny imperfections without skim coating the whole thing. But these should be VERY little imperfections.
__________________
1948 Chevy pickup
Chopped, Sectioned, 1953 Corvette 235 powered. Once was even 401 Buick mid engined with the carburetor right between the seats!
Bought with paper route money in 1973 when I was 15.

"Fan of most anything that moves human beings"
MARTINSR is offline   Reply With Quote
Old 01-02-2017, 02:41 PM   #3
Foot Stomper
Senior Member
 
Foot Stomper's Avatar
 
Join Date: Oct 2015
Location: Calgary, Alberta
Posts: 715
Re: Body Filler Application

In addition to Brian's post which is loaded with great information , put the filler on like it's the only coat it needs because you are working within the product's ability as stated on the technical data sheet you read.

Secondly, you'd be better off to fill one area with a mix or two of filler, then sand it and reapply as required until you're happy with the result. The reason is twofold 1) you have less chance of creating a bunch of repair work due to your inexperience and 2) filler can get harder to sand the longer it's left. It's best to only apply filler that you're sure you can sand same day. It cures pretty fast (about 20 minutes) so planning ahead to sand shouldn't be a problem.

Keep in mind you are going to use a glaze putty (2 part!) when you're done filling so you don't need to get it perfect with the filler. Get the filler to 95% perfect, glaze to 99% perfect then the high build will take you to 100%.

Post pictures of your work...we all like pictures
__________________
So when is this "Old enough to know better" supposed to kick in?

My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989
Foot Stomper is offline   Reply With Quote
Old 01-02-2017, 03:03 PM   #4
clemsonteg
Registered User
 
Join Date: Jul 2012
Location: Anderson,SC
Posts: 886
Re: Body Filler Application

Thank you Brian and Foot Stomper. I have definitely seen that post before. That, combined with reading the back of the can and the data sheets I could find on the interwebs is what spurred my question.

The data sheet says max 1/4" and apply in layers, not all at once. Brian's post also made it seem like it was layered sort of deal. I will work one panel at a time for now.

I put epoxy primer down over the bare metal spots from welding and grinding, so part of my effort to get the filler on at once was to take advantage of the epoxy-filler chemical bond while I was in the recoat window for the epoxy primer. It sounds like I will be better served to abrade the surfaces as I come to them and not worry so much with the chemical bond.
clemsonteg is offline   Reply With Quote
Old 01-02-2017, 03:12 PM   #5
Foot Stomper
Senior Member
 
Foot Stomper's Avatar
 
Join Date: Oct 2015
Location: Calgary, Alberta
Posts: 715
Re: Body Filler Application

The epoxy recoat window is referring to more epoxy, not the filler but a scuff never hurts when it comes to adhesion.

1/4 inch filler is maximum total thickness. Work your sheetmetal more if you're over that depth.
__________________
So when is this "Old enough to know better" supposed to kick in?

My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989
Foot Stomper is offline   Reply With Quote
Old 01-02-2017, 03:26 PM   #6
clemsonteg
Registered User
 
Join Date: Jul 2012
Location: Anderson,SC
Posts: 886
Re: Body Filler Application

Quote:
Originally Posted by Foot Stomper View Post
The epoxy recoat window is referring to more epoxy, not the filler but a scuff never hurts when it comes to adhesion.

1/4 inch filler is maximum total thickness. Work your sheetmetal more if you're over that depth.
Thank you for the clarification. I thought I had seen an Eastwood video where they talked about epoxy and not needing to abrade for filler if the epoxy was within the recoat window. I probably misunderstood what they were saying.
clemsonteg is offline   Reply With Quote
Old 01-02-2017, 10:17 PM   #7
clemsonteg
Registered User
 
Join Date: Jul 2012
Location: Anderson,SC
Posts: 886
Re: Body Filler Application

Here's another question regarding blocking, I should use a block that is larger than the area I have to sand, right? I am assuming that is so I can level the sea I am working on with the surprising metal. There is one wavy area that is nearly 2 ft long, should I use the largest block I have?
clemsonteg is offline   Reply With Quote
Old 01-03-2017, 01:22 AM   #8
MARTINSR
Registered User
 
MARTINSR's Avatar
 
Join Date: Dec 2000
Location: San Francisco Bay area Ca USA
Posts: 2,877
Re: Body Filler Application

It's not the truth at all really. But it takes some to master it. An 18" board is the longest I own but will repair a truck bed side.

Brian
__________________
1948 Chevy pickup
Chopped, Sectioned, 1953 Corvette 235 powered. Once was even 401 Buick mid engined with the carburetor right between the seats!
Bought with paper route money in 1973 when I was 15.

"Fan of most anything that moves human beings"
MARTINSR is offline   Reply With Quote
Old 01-03-2017, 10:08 AM   #9
Foot Stomper
Senior Member
 
Foot Stomper's Avatar
 
Join Date: Oct 2015
Location: Calgary, Alberta
Posts: 715
Re: Body Filler Application

Go to YouTube and search "block sanding body filler" and spend an hour watching the many videos there. An hour invested there will save you a lot of time.

In short, you don't need a block larger than your repair area.
__________________
So when is this "Old enough to know better" supposed to kick in?

My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989
Foot Stomper is offline   Reply With Quote
Old 01-03-2017, 11:08 AM   #10
clemsonteg
Registered User
 
Join Date: Jul 2012
Location: Anderson,SC
Posts: 886
Re: Body Filler Application

Quote:
Originally Posted by MARTINSR View Post
It's not the truth at all really. But it takes some to master it. An 18" board is the longest I own but will repair a truck bed side.

Brian
Quote:
Originally Posted by Foot Stomper View Post
Go to YouTube and search "block sanding body filler" and spend an hour watching the many videos there. An hour invested there will save you a lot of time.

In short, you don't need a block larger than your repair area.
Thank you both. I guess my concern came from watching a few videos and it looked like it would be pretty easy to go too low in the area I am working if the block is smaller than the repair area. I will keep watching videos for sure!

I ordered a durablock kit from Amazon that should be in today or tomorrow. For now, the only block I have is one of the small 3M blocks with the flaps and pins to hold the sandpaper. Seems to work well to start, but I don't trust myself enough to use it without going too low. I know this is something that is learned by doing, so I will get started.
clemsonteg is offline   Reply With Quote
Old 01-03-2017, 01:58 PM   #11
MARTINSR
Registered User
 
MARTINSR's Avatar
 
Join Date: Dec 2000
Location: San Francisco Bay area Ca USA
Posts: 2,877
Re: Body Filler Application

Quote:
Originally Posted by clemsonteg View Post
Thank you both. I guess my concern came from watching a few videos and it looked like it would be pretty easy to go too low in the area I am working if the block is smaller than the repair area. I will keep watching videos for sure!

I ordered a durablock kit from Amazon that should be in today or tomorrow. For now, the only block I have is one of the small 3M blocks with the flaps and pins to hold the sandpaper. Seems to work well to start, but I don't trust myself enough to use it without going too low. I know this is something that is learned by doing, so I will get started.
I still after all these years have a real hard time not grabbing my good old 3M rubber block. Years ago I took one of those rubber blocks and I cut it with a hack saw making two blocks, one an inch wide and another 2 inches wide. Those suckers have been soooooo handy over the years.

Brian
__________________
1948 Chevy pickup
Chopped, Sectioned, 1953 Corvette 235 powered. Once was even 401 Buick mid engined with the carburetor right between the seats!
Bought with paper route money in 1973 when I was 15.

"Fan of most anything that moves human beings"
MARTINSR is offline   Reply With Quote
Old 01-03-2017, 02:28 PM   #12
clemsonteg
Registered User
 
Join Date: Jul 2012
Location: Anderson,SC
Posts: 886
Re: Body Filler Application

Quote:
Originally Posted by MARTINSR View Post
I still after all these years have a real hard time not grabbing my good old 3M rubber block. Years ago I took one of those rubber blocks and I cut it with a hack saw making two blocks, one an inch wide and another 2 inches wide. Those suckers have been soooooo handy over the years.

Brian
I am sure that over the years you have made quite the number of sanding blocks from all sorts of things!

I watched videos during my lunch break and sanding blocks seemed to be dependent on the person, some recommended the largest block that will fit the area (within reason), a block only slightly larger than problem area, and some guys using the same rubber block I have!

I think making things level and the tendency to over sand will be my biggest challenge. It looks like guide coat will be my friend.
clemsonteg is offline   Reply With Quote
Old 01-03-2017, 09:23 PM   #13
clemsonteg
Registered User
 
Join Date: Jul 2012
Location: Anderson,SC
Posts: 886
Re: Body Filler Application

I gave the small rubber block a try tonight and I'm fairly happy with the progress. I have one small spot in the middle that needs a hair more filler. My only problem I am running into are the 2 spots I circled. The filler doesn't seem to be feathering there. Should I add a little more filler in those spots along with the spot in the middle, or should I wait until I do the polyester putty (looking at evercoat metal glaze ultra) and block it in st that point?
Attached Images
 
clemsonteg is offline   Reply With Quote
Old 01-03-2017, 10:18 PM   #14
Foot Stomper
Senior Member
 
Foot Stomper's Avatar
 
Join Date: Oct 2015
Location: Calgary, Alberta
Posts: 715
Re: Body Filler Application

Those spots are too high. If they're too high for surrounding area a body hammer with tap them lower.
You've got a nice feather edge too by the way!
__________________
So when is this "Old enough to know better" supposed to kick in?

My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989
Foot Stomper is offline   Reply With Quote
Old 01-03-2017, 10:30 PM   #15
clemsonteg
Registered User
 
Join Date: Jul 2012
Location: Anderson,SC
Posts: 886
Re: Body Filler Application

Quote:
Originally Posted by Foot Stomper View Post
Those spots are too high. If they're too high for surrounding area a body hammer with tap them lower.
You've got a nice feather edge too by the way!
Thanks! I definitely watched a lot of videos like you suggested and I tried to take my time while I was working.

I took a close up of one of the problem areas. I think the black/gray area (the coat of epoxy primer I put down) is too low and I think it's my fault from not feathering the filler as I applied it. I plan to give it another go tomorrow night if I get some time.
Attached Images
 
clemsonteg is offline   Reply With Quote
Old 01-04-2017, 01:12 PM   #16
Foot Stomper
Senior Member
 
Foot Stomper's Avatar
 
Join Date: Oct 2015
Location: Calgary, Alberta
Posts: 715
Re: Body Filler Application

You're right, it is too low OR the area around is too high... my guess is "too low".
Don't be afraid to spread the filler over an area that's larger than you think it needs. As you sand it down it will come into shape.

Don't rely so much on what you see at this stage but rather what you feel in your whole hand as you run it over the repair area. You will feel low and high spots as well as other imperfections.

I noticed your sand scratches are running the length of the panel and this is wrong. You need to sand at a diagonal to the curve to make a cross hatch pattern while keeping the sandpaper parallel to the floor. This is why and how a 11 inch block works on large panels without needing a 24 inch sanding block. Sand some from bottom left rising up towards top right and then change to the other direction... bottom right up towards top left. You can abraid while moving up and down as the direction of the sanding stroke is what will give you a straight panel.
__________________
So when is this "Old enough to know better" supposed to kick in?

My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989
Foot Stomper is offline   Reply With Quote
Old 01-04-2017, 10:51 PM   #17
clemsonteg
Registered User
 
Join Date: Jul 2012
Location: Anderson,SC
Posts: 886
Re: Body Filler Application

Quote:
Originally Posted by Foot Stomper View Post
You're right, it is too low OR the area around is too high... my guess is "too low".
Don't be afraid to spread the filler over an area that's larger than you think it needs. As you sand it down it will come into shape.

Don't rely so much on what you see at this stage but rather what you feel in your whole hand as you run it over the repair area. You will feel low and high spots as well as other imperfections.

I noticed your sand scratches are running the length of the panel and this is wrong. You need to sand at a diagonal to the curve to make a cross hatch pattern while keeping the sandpaper parallel to the floor. This is why and how a 11 inch block works on large panels without needing a 24 inch sanding block. Sand some from bottom left rising up towards top right and then change to the other direction... bottom right up towards top left. You can abraid while moving up and down as the direction of the sanding stroke is what will give you a straight panel.
Thank you for all of your advice. I got the 2 trouble spots taken care of tonight and I think I am really close to the "last skim" with the putty. Everything to the rear of the wheel feels really good and I'm not going to mess with it anymore. I'm working on a few low spots toward the cab and that will be ready as well. After all of that I should be able to tackle the area on top near that is still in primer.

It's also amazing what the right tools and a variety will do!
Attached Images
  
clemsonteg is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 11:27 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 1997-2013 67-72chevytrucks.com