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benchracer1 Samba Member
Joined: September 24, 2006 Posts: 583 Location: ramona
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Posted: Fri Dec 04, 2020 8:44 pm Post subject: High spots |
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Ive been trying to use as little filler as possible in my bodywork. I am having the problem of coming up with high spots when i sand. Anybody got any techniques to eliminate high spots in advance of filler? Is it something that you just develop a feel for? |
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Chickensoup Samba Member
Joined: January 06, 2018 Posts: 5368 Location: Good Hope, GA
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Posted: Fri Dec 04, 2020 9:19 pm Post subject: Re: High spots |
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a shrinking disk?
btw, im no expert at body work... at all, im just bumping the thread _________________ -'85 c10 5.3 LS, 222 cam, long tubes, x pipe, 3 inch spin tech's
-'05 B5.5 TDI Wagon 17in sport rims ;EGR + BSM + ASV Delete, Stage-2 Tune, straight pipe
'65 Tourist Delivery Build
'66 RIP
'69 RIP
Hosea 4:6 "My people are destroyed for lack of knowledge" |
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67ctbug Samba Member
Joined: January 24, 2016 Posts: 3619 Location: CT
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Posted: Fri Dec 04, 2020 9:56 pm Post subject: Re: High spots |
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High spots in what? The primer? Original paint? The stuff you're blocking might change how I tell you to handle it. If they're in the primer, meaning you're blocking it out and hitting metal, I would say stop immediately, either tap them down with a hammer and dolly to make room for a tad of filler, or put a few more heavy coats of primer to give yourself more material to sand and flatten out. If it's original paint or a respray and you're prepping for primer, I would do nothing and put on quite a few coats of primer, like I said, to give yourself material to sand. I will say this though, do not be afraid of filler. It has its place in bodywork and although you shouldn't be filling potholes with it, I would have no problem coating a quarter panel with it and then blocking it all off to fill in just the lows and bring everything level. You aren't trying to build up the panel, but put enough on that you can comfortably bring the lows up to the highs and bring the panel up to the highs. That's only if the highs aren't like 1/4" above everything else. When you're blocking too, make sure to use a guide coat. I'm sure you are, but don't go just off feel. Your mind can play tricks when you feel different textures like bare metal compared to primer and plastic filler. _________________ '67 Beetle L41
'74 Westfalia
'69 Plymouth "Adam-12"
'63 Ragtop
'73 914
'73 Dodge W200
'72 Dodge Wrecker
Go Cubs!
World Series Champions 2016
KentPS wrote: |
...or the PO envied the terrorists' bus in "Back to the Future". |
mukluk wrote: |
He's fine, just waiting for the dragon in winklepickers to move out of his lane. |
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Bulli Klinik Samba Member
Joined: January 16, 2005 Posts: 2077 Location: Bulli Klinik, Colorado Springs
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Posted: Sat Dec 05, 2020 9:44 am Post subject: Re: High spots |
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benchracer1 wrote: |
Ive been trying to use as little filler as possible in my bodywork. I am having the problem of coming up with high spots when i sand. Anybody got any techniques to eliminate high spots in advance of filler? Is it something that you just develop a feel for? |
Block the panel before doing filler work. This is part of metal finishing prior to paint.
In your circumstance, consider using the hollow of a skateboard wheel under the high spot and gently tap down. If done right, this captures the perimeter of the high spot and you will be able to shrink it a bit.
In the Porsche video, Made by Hand, you can see the final bodywork guys slightly tapping down high spots with no dolly in preparation for paint. _________________ I've never met a Bus I didn't like.
Mike K
Bulli Klinik
Colorado Springs |
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benchracer1 Samba Member
Joined: September 24, 2006 Posts: 583 Location: ramona
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Posted: Sat Dec 05, 2020 11:55 am Post subject: Re: High spots |
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I think ill try thr shrinking disc for a few and see what happens |
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infiniteLoop Samba Member
Joined: October 09, 2020 Posts: 265 Location: Empire State
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Posted: Sat Dec 05, 2020 5:52 pm Post subject: Re: High spots |
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You can hammer and dolly it down but it takes a long time because it has to be done very slowly. Also ,if you use heat ,only heat it to blue because if you get it hotter it will make the stretched area worse. |
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benchracer1 Samba Member
Joined: September 24, 2006 Posts: 583 Location: ramona
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Posted: Sun Dec 06, 2020 6:09 am Post subject: Re: High spots |
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Also another quick question. Will using a hardwood slapper on dolly stretch metal or just move it? |
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Evil_Fiz Samba Member
Joined: May 06, 2011 Posts: 1045 Location: Jacksonville, FL
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Posted: Sun Dec 06, 2020 5:37 pm Post subject: Re: High spots |
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benchracer1 wrote: |
I think ill try thr shrinking disc for a few and see what happens |
A shrinking disc will work wonders on high spots but use it carefully an slowly. It is easy to go too far with it and make matters worse. I learned this the hard way when I created a low spot that I can't get behind to dolly out.
-----
Emil _________________
It's not just about what's interesting. It's also about what's helpful, and it's helpful even if it helps just one other guy working on a Ghia.
kiwighia68
See my build on TheSamba at:
The K_R_A_K_E_N_N : a 70 Ghia Convertible reinterpreted |
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infiniteLoop Samba Member
Joined: October 09, 2020 Posts: 265 Location: Empire State
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Posted: Sun Dec 06, 2020 6:06 pm Post subject: Re: High spots |
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benchracer1 wrote: |
Also another quick question. Will using a hardwood slapper on dolly stretch metal or just move it? |
If you are hitting a area with a lot of ups and downs with a slapper; because the slapper is big and covers a large area , you can do 'hammer on dolly' because you really are not hitting the dolly until the ups and downs are flattened out.
On the topic of 'Moving a stretched area', it's not really possible. If you are pushing a stretched area down or vise versa ,it may change another area somehow but it is by mechanical means. If you had actually shrunk a desired area ,the stretch would be gone.Unless you completely understand whats going on with the dynamics of the panel ,the secondary forces will not be under stood, Like when you try to get a stretched area out but the panel bends somewhere else as a result of this force. It's a one thing leads to another scenario and it's not understood why. |
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VeeDee Samba Member
Joined: February 02, 2020 Posts: 212 Location: Wolfsburg, Germany
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Posted: Mon Dec 07, 2020 10:34 am Post subject: Re: High spots |
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I use a carbon electrode for shrinking the high spots.
Actually, I have to straighten all of the screwed-on body parts for a 51. Some of those were misused by a hammer/dolly actor, the metal was stretched beyond limits and I have to use heat for shrinking, which is precisely transferred via the carbon electrode to the high spots. _________________ Always Aircooled
VeeDee |
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Bulli Klinik Samba Member
Joined: January 16, 2005 Posts: 2077 Location: Bulli Klinik, Colorado Springs
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Posted: Tue Dec 08, 2020 9:35 am Post subject: Re: High spots |
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I just re-read your initial post. For some reason I assumed you had already applied filler.
If the stretch is significant it should be shrunken with a torch then planished into the panel. I describe the technique in my Vanagon build thread:
https://www.thesamba.com/vw/forum/viewtopic.php?t=...;start=100
If your highs are minor and the panel is very close to straight, it's time to use the steel slapper and a closely shaped dolly to planish the panel. This will do two things; blend the minor highs and lows and it will stress relieve the panel. I like to use Dykem on my panels so it becomes obvious where the highs and lows are.
For example, after roughing in this fender, it's sprayed with Dykem then filed to reveal minor lows.
These are bumped up then the panel is planished overall until the lows are gone. A couple coats of poly will fill any remaining imperfections.
Good luck and post some photos of what you're working on. Makes it easier to give advice. _________________ I've never met a Bus I didn't like.
Mike K
Bulli Klinik
Colorado Springs |
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benchracer1 Samba Member
Joined: September 24, 2006 Posts: 583 Location: ramona
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Posted: Tue Dec 08, 2020 7:05 pm Post subject: Re: High spots |
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Wow, that fender looks great. I had pretty good luck with the shrinking disk. Im also thinking Imay be oversanding the filler. I think that in a few cases I might be mistaking oversanded filler for high spots. Ill try and post some pics....Steve |
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benchracer1 Samba Member
Joined: September 24, 2006 Posts: 583 Location: ramona
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Posted: Sat Dec 12, 2020 7:49 pm Post subject: Re: High spots |
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I finally got some pics. I mellowed out on the sanding and worked on smaller sections. I did have a couple high spots but not as bad as i firdt thought. I'll get her primed tomorrow and see what happens...steve
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evanfrucht Samba Member
Joined: July 24, 2016 Posts: 2180 Location: Laurel Canyon, CA
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Posted: Sat Dec 12, 2020 9:34 pm Post subject: Re: High spots |
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You can do more bodywork with hammers and dollies to bring some if the high spots down a little. But that may not be needed.
One thing is that many people have a habit of sanding down the filler to quickly or aggressively. If you sand too much off you end up having this problem.
To be safe you could reapply a skim coat and carefully sand it down with a flexible long block. Put sandpaper on hood curve, and bend block against the area as you apply sandpaper to the block and the sticky/velcro will help it keep shape. Something like a durablock or similar.
Technique is everything here. You don't want to sand too much of the the filler off. Also apply it all the way past the edges. You need to be able to "feather" it in.
Overall it looks like you have the right idea.
You dont want filler to ever me more than about 3/16" thick once sanded down. Ideally 1/8 " ... that may give you an idea of how close the metal work is. If its thicker that that then you need to do more work on the metal. _________________ 1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder ) |
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