Dressing Welds with All Metal and Epoxy Primer

O

Outlaw

Im in the process of using an acid brush to dress welds before applying "All Metal". I induce the epoxy after its been 70 degrees or above over night. Meanwhile I spot blast the weld. Once my heat lamp brings the metal temp up to 70 degrees, I apply the SPI epoxy with an acid brush. This process worke the epoxy into all the voids. I honestly think the epoxy alone would be sufficient to water proof the weld but just as insurance, I wait 24 hours and apply "All Metal". Since the Epoxy applied with an acid brush goes on quite heavy, is 24 hours at 70 degrees or above adequate time for the epoxy to cure? I can easily get temps of over 100 degrees with my heat lamp, but its time consuming since I only have one heat lamp. Still fighting the cold weather here in Montana.
 
Once the epoxy is on the metal and inside all weld porosity on BOTH sides, All-Metal is entirely unnecessary. It's just bondo with aluminum dust in it anyway, it's not waterproof. The epoxy does all that needs to be done. If you feel like you need to do more, sand the epoxied area and continue to dab more epoxy into any remaining holes. Repeat until they are gone. On the backside, once two coats of epoxy are on the area, seam sealer can be tooled into any remaining porosities if a perfect finish is not required.
 
+1 on the all metal, its not needed.

Do you have an excessive amount of porosity in your welds?
 
Hi Outlaw,

First, I believe "all metal" filler states in the directions it needs to be applied to metal, if it's the brand I am thinking of.
Is your need to have the welded areas covered with filler to cover/smooth them? I'm assuming you are talking welds like a line and not spot welds.

Mike
 
if the welds are that bad I would suggest practicing and maybe changing to a flux core wire and grinding it down and welding again. I agree on All Metal, any metal filler is supposed to be applied to metal.
 
I've had very good results with Lincoln flux core when not using argon/co2 as it's very clean in regards to splatter. For small welds flux core is all I use.
If you feel adventurous, try leading the next time even though it is a dying art. It's so easy to do but you have to be mindful of the surface type to solder (ex: broad flat area vs. a more rigid areas) to avoid warping. Most of my welded seams are leaded and on one of my cars I did back in the early 80's those areas are as if there was no lead on them at all. Lead is permanent and expands/contracts at the same rate as sheet metal and when smoothed right you do not need any fillers. But, in delicate and large flat areas that can be subjected to warping, if not leaded right, today's fillers are perfect and will outlast us if done properly. I'm not so convinced that on a modern car with thinner gauge sheet metal leading will work without warping however.
 
I will blast it out, double check for any pinholes I may have missed, and go with just epoxy.
 
Mike, I have not attempted leading yet but interested. I can butt weld sheet metal with no filler rod and have a perfect fitment, but can not master doing it with no warpage. I used a Henrob welder to do that but pretty much gave up on it becasue of the warpage. Because of this, I have avoided the leading. I use easy grind .023 wire with argon/co2 and get very little splatter and decent welds, but often find "pin holes" when I can get a light behind my weld. My restorations, so far, are on three 56 Ford Trucks, all in various stages of restoration. Lots of big flat areas. The porosity problem is where I have attempted to close stock seams by welding them shut. Ghosting of those seams is a big concern and I got lots of input from members who offered various options.
 
One correction to my post, the product I used is Evercoat Metal to Metal, It clearly states on the can, "Waterproof". This was why I chose it over other options that did not specify "waterproof".
 
Outlaw;n83361 said:
Mike, I have not attempted leading yet but interested. I can butt weld sheet metal with no filler rod and have a perfect fitment, but can not master doing it with no warpage. I used a Henrob welder to do that but pretty much gave up on it becasue of the warpage. Because of this, I have avoided the leading. I use easy grind .023 wire with argon/co2 and get very little splatter and decent welds, but often find "pin holes" when I can get a light behind my weld. My restorations, so far, are on three 56 Ford Trucks, all in various stages of restoration. Lots of big flat areas. The porosity problem is where I have attempted to close stock seams by welding them shut. Ghosting of those seams is a big concern and I got lots of input from members who offered various options.
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Here are some tips on eliminating porosity in mig welds. http://www.thefabricator.com/article/arcwelding/22-possible-causes-of-weld-metal-porosity
Are you sure it's porosity not just voids from where you are spotting/stiching the welds together? I've got a Henrob (Cobra DHC) as well and yes there is a learning curve and yes you get warpage but the idea is that you dolly the warpage out as you are working. Check out Peter Tommasini's DVD's. Here is a short Vid of him explaining gas welding. https://www.youtube.com/watch?v=fkNtUjxSf7Q
 
Chris, its voids from where I am stiching the welds together. Thanks for the information, I will check those links out. Welding sheet metal is a real challenge for me. I can do a decent job with its a patch I have fabricated and have minimum to no pin holes. Its when I attempt to close a stock seam or with a gap larger than what I can produce with a patch panel,.
 
Outlaw;n83366 said:
Chris, its voids from where I am stiching the welds together. Thanks for the information, I will check those links out. Welding sheet metal is a real challenge for me. I can do a decent job with its a patch I have fabricated and have minimum to no pin holes. Its when I attempt to close a stock seam or with a gap larger than what I can produce with a patch panel,.
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We had some 1/4" copper bus bar laying around that we held on the back of the welds to absorb some of the heat until he really got good at welding.
 
In the areas I have difficulty, I can not get a piece of copper behind the weld.I love copper heat syncs when I can use them.
 
Outlaw;n83363 said:
One correction to my post, the product I used is Evercoat Metal to Metal, It clearly states on the can, "Waterproof". This was why I chose it over other options that did not specify "waterproof".
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Take claims like that with a grain of salt, especially since you have the correct means at your disposal and are already halfway there with your procedure. The only reason the aluminum fillers exist is because they look a lot like lead when sanded and make it appear that work has been done "old school," it allows people to claim, somewhat falsely, that "no bondo was used," when in fact we all know that polyester filler is polyester filler, even if it LOOKS like metal or lead.
 
crashtech;n83371 said:
Take claims like that with a grain of salt, especially since you have the correct means at your disposal and are already halfway there with your procedure. The only reason the aluminum fillers exist is because they look a lot like lead when sanded and make it appear that work has been done "old school," it allows people to claim, somewhat falsely, that "no bondo was used," when in fact we all know that polyester filler is polyester filler, even if it LOOKS like metal or lead.
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I usually go by the hardeners though. Metal 2 Metal has a liquid hardener like fiberglass resin, so I think they are more waterproof than Bondo fillers would be with metal shavings. Other aluminum dust added bondos use cream hardeners.
 
anotheridiot;n83375 said:
I usually go by the hardeners though. Metal 2 Metal has a liquid hardener like fiberglass resin, so I think they are more waterproof than Bondo fillers would be with metal shavings. Other aluminum dust added bondos use cream hardeners.
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If in fact it was an aluminum anything touching steel it would be a disaster. I will never use any of the marketed crap.
 
anotheridiot;n83375 said:
I usually go by the hardeners though. Metal 2 Metal has a liquid hardener like fiberglass resin, so I think they are more waterproof than Bondo fillers would be with metal shavings. Other aluminum dust added bondos use cream hardeners.
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This polyester resin uses cream hardener. I don't think it is any less waterproof than resin with liquid hardener.

http://uschem.com/products/docs/TDSUSC58215_ALL_RESIN1.pdf
 
DATEC;n83378 said:
If in fact it was an aluminum anything touching steel it would be a disaster. I will never use any of the marketed crap.
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I am going to remove all the metal to metal aluminum filled filler and go with just epoxy, but, out of curosity, why is aluminum touching steel a disiaster?
 
wow, never heard anything like that unless there was flowing water included, i.e copper to iron pipe. I do know when we did some work on my sisters old honda civic there was a magnesium post between the seats and there was hardly any rust on the body, just brake and fuel lines.
 
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