Recent Topics
Ford 4.6L Durability?
by Auae85
Yesterday at 11:00 PM
Mercedes Benz High Mileage Badges
by Snagglefoot
Yesterday at 10:46 PM
Lawn Tractor Tire Sealer
by 97K15004WD
Yesterday at 10:01 PM
Fireworks Stores
by Warstud
Yesterday at 09:36 PM
1994 Ranger fuel tank/frame cleanup & NOS part
by 01rangerxl
Yesterday at 09:27 PM
Koreans top J.D. Power qlty; Ford, GM, FCA make strides
by wemay
Yesterday at 09:18 PM
How Fast to Run a ZeroTurn Mower
by Gebo
Yesterday at 09:10 PM
Bosch 3300 C&P Yamaha FZ-07
by bmwpowere36m3
Yesterday at 08:49 PM
My FIL in hospice
by fdcg27
Yesterday at 08:41 PM
Spraying Polyurethane
by Texican
Yesterday at 08:37 PM
Dehumidifier icing
by Kestas
Yesterday at 08:37 PM
Diesel lube in Petrol Engine
by Ducked
Yesterday at 07:46 PM
New key programming cost
by 92saturnsl2
Yesterday at 07:27 PM
When you help someone and its time to walk away
by RazorsEdge
Yesterday at 07:09 PM
Sightly overfilled oil..ok or drain?
by flinter
Yesterday at 07:08 PM
Wheel says 50 mph max
by pda1122
Yesterday at 06:54 PM
15w40 Maxlife in Motorcycle
by Brian553
Yesterday at 06:39 PM
BITOGer in Ottawa/Orleans Canada area ? ...
by Papa Bear
Yesterday at 06:36 PM
Old Engine SOUND
by MasterSolenoid
Yesterday at 06:06 PM
ProMotive PH 2500 CUT OPEN
by car51
Yesterday at 04:54 PM
Newest Members
yamahaboy125, Turboholic, TrpNY, bcj, Ilia
65282 Registered Users
Who's Online
36 registered (BoiseBound, alarmguy, billt460, bullwinkle, CB900F2, Blue_Goose, 5 invisible), 894 Guests and 34 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
65282 Members
67 Forums
285683 Topics
4767793 Posts

Max Online: 3590 @ 01/24/17 08:07 PM
Donate to BITOG
Topic Options
#4462222 - 07/17/17 07:45 PM Will Bondo Spot Putty adhere to bare aluminum?
Mr_Accord Offline


Registered: 01/24/07
Posts: 446
Loc: LBP
I have a set of old mirrors for my SAAB where the painted aluminium finish has started to peel away from the assembly revealing the white aluminium oxide build up underneath. I have used some aircraft paint stripper and a brass wire wheel to clean the whole frame down to bare metal. The oxide has left some small pitting and pin holes over certain areas of the surface. Its a bit too much for any etching primer/paint with filler properties to take care of, but also a bit too much for body filler. Will glazing + spot putty stick to bare aluminium or do I have to etch prime it first?

Thanks
_________________________
1990 VW Jetta GL 1.8L 8V - SOLD
1992 Honda Accord Lx - SOLD frown
1993 Ford Aerostar XL 4L V6 - Retired RIP
2004 SAAB 9-3 ARC 2.0T - Current

Top
#4462236 - 07/17/17 08:05 PM Re: Will Bondo Spot Putty adhere to bare aluminum? [Re: Mr_Accord]
Linctex Offline


Registered: 12/31/16
Posts: 6148
Loc: Waco, TX
Bondo will work for a year or two, but if you have "small pitting and pin holes", use JB Weld instead.
_________________________
"The evidence demands a verdict".
(Re:VOA)"it's nearly impossible to actually know the particular additives that are in there at what concentrations."

Top
#4462289 - 07/17/17 09:01 PM Re: Will Bondo Spot Putty adhere to bare aluminum? [Re: Linctex]
Mr_Accord Offline


Registered: 01/24/07
Posts: 446
Loc: LBP
Originally Posted By: Linctex
Bondo will work for a year or two, but if you have "small pitting and pin holes", use JB Weld instead.


JB weld can be sanded and painted over?
_________________________
1990 VW Jetta GL 1.8L 8V - SOLD
1992 Honda Accord Lx - SOLD frown
1993 Ford Aerostar XL 4L V6 - Retired RIP
2004 SAAB 9-3 ARC 2.0T - Current

Top
#4462290 - 07/17/17 09:05 PM Re: Will Bondo Spot Putty adhere to bare aluminum? [Re: Mr_Accord]
SVTCobra Offline


Registered: 12/11/09
Posts: 701
Loc: Battle Creek, MI
Yes. I've used it in painted applications a couple of times and never noticed any differences. I would sand it and prime first to do a better job.
_________________________
If marriage was outlawed only outlaws would have in-laws.

Top
#4463757 - 07/19/17 09:29 AM Re: Will Bondo Spot Putty adhere to bare aluminum? [Re: Mr_Accord]
Linctex Offline


Registered: 12/31/16
Posts: 6148
Loc: Waco, TX
Originally Posted By: Mr_Accord


JB weld can be sanded and painted over?


Yes - push it "into" the pin holes and it will never "fall out" like bondo will.
_________________________
"The evidence demands a verdict".
(Re:VOA)"it's nearly impossible to actually know the particular additives that are in there at what concentrations."

Top
#4466687 - 07/21/17 09:06 PM Re: Will Bondo Spot Putty adhere to bare aluminum? [Re: Mr_Accord]
OilSwag Offline


Registered: 07/02/17
Posts: 43
Loc: Tennessee
Everclear > Bondo
Bondo is lacking in the quality department. Many premium, longer lasting, easier to use products out there. Not just Everclear but I suggest using almost any good branded body filler over Bondo. It was good stuff compared to what was around in like the 80's. All those cars you see with body filler dropping out, cracking etc is almost always Bondo brand
_________________________
03 Infiniti G35 209K, Castrol Edge 5W30 topped with Edge HM, Fram Ultra Filter, Berryman/MMO fuel maintenance in 93 E0, all synthetic fluids

Top
#4466697 - 07/21/17 09:16 PM Re: Will Bondo Spot Putty adhere to bare aluminum? [Re: Mr_Accord]
CT8 Offline


Registered: 10/09/14
Posts: 10967
Loc: Idaho
look up Alodine before you do any work on the aluminum.
_________________________
"Don't let your preconceived notions get in the way of facts."
Geoff Metcalf

Top
#4466971 - 07/22/17 09:23 AM Re: Will Bondo Spot Putty adhere to bare aluminum? [Re: Mr_Accord]
Trav Offline


Registered: 11/20/06
Posts: 18873
Loc: MA, Mittelfranken.de
Once the aluminum is bare and wire wheeled wipe it down with vinegar and dry it, the mild acid will remove any light oxidation in the "pores" of the metal, immediately apply JB weld, oxidation occurs quickly so do right away.
Sand down the jb weld with a dremel, orbital sander or by hand then apply self etching primer, now you apply filler over the etching primer to any remaining defects. Another couple of coats of etching primer and then refinish with primer filler, paint and clear.

I see there is a debate on the quality of filler, first its all the same base materials in different quantities, talc being one of the primary ingredients and that's the problem with polyester fillers.

Some are easier to sand, have fewer air bubbles but all will absorb moisture (including the so called metal fillers) as does one part primer fillers, the trick to long lasting repairs with fillers is to encapsulate it. If there is one step to successful rust repair this is it, we see it all the time a rust repair only lasting a short time before rust starts coming back through the paint in the form of bubbles, many times when you pop these water comes out and when you grind it down you see the repair patch is still in tact with no further rust through, what happened?

Once the panel was welded and patched it looked great so its all ground down and "bondo" applied. the repair is doomed to fail at this point. Any pin hole anywhere in the seam of the patch will now allow the filler to absorb moisture (even from the air) from behind and wick out under the paint.
A coat of epoxy like JB weld over the entire seam inside also if possible will ensure the filler remains dry. Sand the JB down its only to fill any sort of pin holes which almost always happens even if you cant see them when welding thin sheet metal.

Once the JB weld is sanded down apply a self etching primer to the whole area then apply the filler, you have now sealed the filler from behind. apply a good quality 2k epoxy primer then a poly primer over that to finish the job then paint. The filler is sealed from both sides and the repair will last a very long time.

Back when I first started we brazed a lot of panels and it was not as big an issue, we also used lead filler on some higher end cars. This worked great on thick sheet metal but today its very difficult, panel distortion and the dangers of working with lead are nothing for the DIY or even most pro's today have never been taught how to use lead and more important use it safely. Pick and file work is nothing on new cars the metal isn't thick enough so they don't teach it anymore either.
_________________________
ASE L1, Master. Deutsch Meisterbrief.

Top