Butt vs. Lap Welding for Rust Repair: The Debate Ends Here! 

Thanks my friend - I appreciate that. Have a great weekend :)

You're welcome. Gotta love the riffs of the 70's and 80's even 90's and 2000's - Like "Bullet For My Valentine" - Hearts Burst into Fire - crazy good stuff :)

You're welcome - glad you like them - have a good weekend :)

I appreciate that - have a great weekend :)

Glad it was helpful - I tried to be as fair as possible - just stuck to the facts. Have a great weekend :)

You're welcome :)

That's just great to hear - honestly this is how it was and is done in most good body shops today. The internet is filled with not so great ideas and methods 😊

You're welcome Joe, glad it helped :)

You're welcome Jim - thanks for the support. Have a good weekend :)

Excellent adage! I'll have to remember that - so many times "perfection" will prevent folks from even starting a project. Well said. You'll be perfectly fine using the methods found on this channel. Many quality shops in Michigan use the same - that's where I learned them. Thanks for the comment and support :)

You're welcome and thanks for the kind words and support. I don't say this in any video but in my time working at some major shops in the metro Detroit area, I have never watched anyone try to butt weld a patch - never. Truthfully, the guy would not last long at all. Sure you butt weld when you need to - like edges, rigid panels like rockers, wheel well lips, etc. Most of the times however, you'll be lap welding. Remember, there are over 5000 welds in a car being built in a factory and not one is a butt weld - there's a reason for that. Thanks again and good luck with your projects - Jerry

You're welcome - you're right, if you seal the back side you'll be fine. No moisture - no rust :)

Thanks Moparnut62, you're right - the salt on the roads is a real bummer. The mist coats brake lines, fuel lines, brackets, etc. I'd like to purchase a TIG welder but they're pretty expensive

I appreciate your comment Gary - have a good weekend :)

You're welcome :)

Thanks - You're right - filler is used every day in dealerships across the country but you don't know it 'cause they apply it correctly.

Important to note that only works if there isn't a 3rd sort of "gusset'y" panel between the inner and outer rocker/sill.

You're welcome JDP - thanks for your input. Happy New Year :)

Thanks Mitch - I appreciate the support :)

Thanks Husky - I'm glad you liked it - stay safe too and have a great week :)

Thanks - always good to hear from you :)

Thanks wild west. Here's some more good info on longevity of lap: Eastwood’s explanation on butt weld and metal finish: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rpH50kh4W00.html *** For longevity of the lap repair see: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8XaZBy7GC7A.html

Thanks - I appreciate that. Mike Fn Garage has a cool channel - lots of cool VW's - that's nice of him to mention my channel - very cool - I'll have to thank him. Have a great weekend.

@@LakesideAutobody you also

Thanks Curtis - have a good weekend :)

You're welcome :)

You're welcome :)

You're welcome - Never heard of a Business Coupe - had to look it up - very cool car. It's always a good idea to invent allow for drainage like you said. After the repair you can rust proof like in this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8XaZBy7GC7A.html Let me know how your project goes and If you have any ?s feel free to ask - doesn't matter what video - I answer 1-2 times a day :)

Let me know how it goes for you with the flange too. Do a patch with the flange tool and one without and let me know how you feel about it after each - Merry Christmas and HNY WKW Jerry

Have a good weekend PK :)

@@LakesideAutobody you have a good weekend as well!

Totally agree!

Punch and flange tool has saved countless hours for me, getting patches flush. Best $50 I ever spent for body work! It won't fit everywhere, but it still helps making holes to screw the patch up right.

Thanks Erich. You're right about something not working on every repair - a good reason to know every method. So glad you liked the video - you rock too :)

Me too.. lol

Jerry always Rocks ! 🎸👍

You'll be fine doing it with lap welds 👍🛠😊

You're welcome - glad you liked it - have a good weekend :)

Thanks for your input LCPD - have a great week :)

Thanks Jeff - You might appreciate this video on older cars: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-fHgUG_fhvuI.html

Hi Al, good to hear from you. I've made wasted trips like that too my friend. I do wish there were more of those cars around to take on as a hobby but man... they're either a fortune or a basket case. Glad you liked the video Al - have a good weekend - and thanks :)

Well said - have a great weekend and thanks for the support - Jerry

Yeah you may not have run into factory butt welds, because from the factory they produce complete panels. There was no need for a butt weld. But in the real world, to keep the metal the same thickness without excessive filler a good butt weld with the correct way to do a repair. Don't let Mr. slap a 1/4 inch of bondo man cloud your thinking.

@@mypointofview6056 Today’s metal is .030. That is literally 6 hairs (hair is .005) thick. You start grinding on that and the result is paper thin welds & surrounding metal. Your goal is to have methods to fix anything . Surely you’re not going to butt weld and metal finish this: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-36zkc9UQaTs.html or some of my other rust repair videos. Use small overlap, weld solid, tap welds down, use fiberglass reinforced filler and you won’t have to worry about moisture - especially if you keep the drain holes clean (most important thing in rust prevention). Note that the opening of the seam is upside down on the inside (no moisture trapped). See these videos for longevity of this type of repair if done correctly: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8XaZBy7GC7A.html ***** www.youtube.com/watch?v=2o37dX-

Upside down seam? One word: capillary action ....(ok that's two words) Also, how do you manage to get the seam upside down all the way around the patch? Either way, if you're not treat the inside of the panel is gonna rust. Love the videos

@@clmym00 Thanks Myles - true the cap action probably happens but it dries out as opposed to being trapped. Does that "hold water" - no pun intended :) Jerry

Thanks 👍😊✌

Great to hear Jeremy - let me know how your projects go and if you have any ?s - have a great weekend :)

@@LakesideAutobody glad to now understand why I got bubbles on some repairs... I found out you can't spray 1k clear over 2k clear a day later.. I was a little light, matte, on one section of clear I sprayed with spraymax 2k, ran out and tried to finish that section off with another coat of duplicolor clear next day. it reacted and melted all the way though the base coat. What a mess, Lol.. good thing it's the 02 civic project car. Had to do a quick and dirty sand and repaint on that section

@@LakesideAutobody sorry, I did have a question.. if you spray the back with oil and there are pin holes will the oil seep in and ruin the body work and paint.. maybe only if it's a new repair, maybe wait till later?

@@jeremyr7147 No - you're fine - at least I've never had a problem doing that. In fact, the sooner the better - don't even give the elements a chance! I use average quality materials too - so if you're using 2K primer and paint - even better. Try it in a small area for a day or two - wipe off the residue and see how the finish is doing - if it's fine then go for it :)

@@LakesideAutobody thanks!! Funny I just had a newer volvo c30 pull in the rear tires bald and toed in about 10 degrees on one side from a parking lot hit... had it all fixed and alignment straight in no time thanks to all I've learned. Straightened the subframe and had plenty of room in alignment adjustment to get it straight. He's gonna have me do his body work and paint in the near future too. Pretty fun day and I guess I work for the pride and accomplishment.

How do thin out the fluid film to spray it ? - I bought a gallon but have not read the instructions yet - the stuff is like Crisco.

Here's two videos on it - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-y2WSpGFVRPM.html **** ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-hkESVLqypLc.html Thanks for the support. If you don't have to worry about the drill bit popping through and damaging something, the drill bit method is cheap and easy. Let me know if this helped - if now ask again. Jerry

Thanks Big88 - enjoy the weekend 🏈😊

Hope you did as well Sir!!@@LakesideAutobody

Thanks :)

Thanks for the support Jim. I would love to see that part of the manual - If possible could you send me a copy of that page to schoolvideolibrary @ gmail dot com - Jerry I would greatly appreciate it :)

@@LakesideAutobody yes sir, I'll be happy to :) I might even show you some pics from my car build

@@jimbob3708 I would love to see the car build pics - thanks a lot and have a good weekend Jim :)

@@LakesideAutobody probably bent some copyright laws, but.. to hell with them.

@@jimbob3708 Thanks so much Jim - I'm looking it over right now - have a good week :)

Well said. Couldn't be said any better. Thank you for sharing that.

Treating the repair after the paint is very important - something greasy or oily that sticks and self heals or creeps into the gaps. Good point.

@@LakesideAutobody Try Chan saw bar oil. It's liquid enough and clings tenaciously

@@jimurrata6785 Very good - squirt some of that inside of a panel and your good for a long time :)

@@LakesideAutobody With the right bottle from your recycle bin you can even get a choice of stream or spray. 💡 It is vicious though, so don't pull the trigger too hard or you will snap it off. DAMHIK. 😉

I contacted a company and they're in the process of making up a logo for hoodies, hats, and t's - I should have a link w/in couple of months. Thanks so much for the support and you're welcome - Jerry

Thanks. I think all methods can work if done right. .I think magazines, television, and internet are really lying to folks when they claim there's only one way. If you examine how the rust will begin again you can stop it. No moisture = No rust. Thanks for your opinion - your right - everything is going to deteriorate - how long can you prevent it from happening is the challenge and the focus :)

this is also a great practice..if you are going to use plastic on a panel.. tinning the panel area, will keep any rust from forming.

No problem - my email is listed under the "about" tab on the home page. Some folks say it doesn't show up - let me know if it doesn't. Jerr

@@LakesideAutobody Hi Jerry. I sent the email over this morning. The email was not visible on phone in RU-vid app, I had to use desktop browser to see it after clicking I'm not a robot and then clicking submit button.

@@sayjackTux OK - sorry about getting to this message late - was busy all day :)

Very interesting - were do you get the fish oil? Does it smell at all?

@@LakesideAutobody here in Australia most auto shops and hardwares sell it. theres two types , the fishy smell and the deodourised, both smell for weeks. others spray lanolin : the oil from wool. both smell but pretty much prevents rust for along time. no panel beater spray painter would use it, they make the car smell.

You could cut it out and try either lap welding or glue. See this video for gluing: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-wRl1QfkrBeY.html

@@LakesideAutobody Could I possibly just grind the rust off, reseal it and repaint? Or will it potentially not keep the rust away?

@@michaelbolia7847 It'll just keep coming back because the moisture is coming from the back side. However, if you did what you are saying PLUS seal the back (clean it and spray with good rubberized undercoating like 3M or SEM) it would work. Let me know what you end up doing - curious :)

I don't use weld through as I prefer to treat the inner panel for rust "after" the repair - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8XaZBy7GC7A.html We were always told (bosses) to unhook the negative cable on the battery before MIG welding. Since the 80's I've always removed the neg cable and never have had one issue. Hope that helps - Jerry

@@LakesideAutobody that does help that you! So many say to unplug the modules. The vehicle is 18 years old that I am going to work on. It doesn't seem to work out well on really old connection to disturb them been my experience. Thanks for all your videos!

@@weloveups831 You're welcome my friend :)

Thanks for the ideas JG - have a good weekend :)

Here's some good, honest advice. If you want to be the best body man you can be, never be afraid of using filler. That's just magazine, TV talk. Filler is used every day in every dealership and pro body shop across the nation. Most folks don't realize this because these are professionals that are using it - it's being used and applied correctly. If used right it will never be noticed and last forever :)

In my experience, the lap welds do distort less, because there is more metal left to give strength and support to the joint. With more metal there, your welds are more likely to grab onto something, and there is more metal to absorb the heat. Jerry knows his stuff, give this a try and you'll see! Good luck!

You are always going to have a little bit of warping. My advice is to tack it like you do - then alternate from one end to the other do a little run here the a little run there back and forth. The solution is lap weld it, tap down any high areas and fill. That's the most consistent, fastest, long lasting method. You can also try panel adhesive too - a lot of shops are patching with that now.

Blowing air around the weld to cool it helps a lot.

Thanks Snake Doc - have a good weekend - thanks for your support - appreciate it :)

Fiber resin discs on a 5" high speed sander. 1) Astro Pneumatic 222S 5'' High Speed Sander 2) 4-1/2" X 7/8" ALUMINUM OXIDE RESIN FIBER DISC - 25 PACK 36 grit from Benchmark Abrasives

Interesting..... My dad used to braze - what do you like about brazing? What are the advantages?

@@LakesideAutobody I used to primaraly because it was showed to me that way. Tac and braze. The advantages are less warpage and in those rust pit prone areas that are waiting to happen, it bleeds its way in as long as you butt the metals. The funny thing is, at one time, they used to lead ladel, use bees wax and wood to sculpt, then came body filler. I actually saw an old time doing on a chop top and thought, why? Isn't the car heavy enough. After all, it was a late 30's hardtop. lol. Then again, it simply is what you are taught or learn. I'm sure in his mind, he thought it was better then filler.

I have never done that. It could be a solution to any water penetration though - have you tried it?

@@LakesideAutobody hey thanks for replying , well I’m a retired plumber practising on an old work truck that I have and hopefully get a nicer rat rod so l can work on one day, however I did us seam sealer and rivets on some of the panels and put body filler on top. Looks ok but not sure how it goes in the future😁

@@abdulhamoui4376 You're welcome - hope you find a cool old rat rod - working on cars is a good hobby - keeps you out of trouble when you retire :)

@@LakesideAutobody thanks dude! Keep up the great work

@@abdulhamoui4376 You're welcome my friend - have a good night :)

If you are sectioning it across the sail panel then absolutely. Any sectioning you would lap, grind the welds to knock them down a bit, tap down the seam and fill. Around the perimeter you'll spot weld through holes pre drilled in the quarter flange, etc. Let me know it that makes sense or if it helped at all. Jerry

@@LakesideAutobody is there an email I can get in contact with you? I’d really like your help this is my first project and I’m pretty nervous

@@LakesideAutobody also yes thank you very much for this info

@@jah2029 Yes - my email is located under the "about" tab on my home page. If you can't access it let me know - Jerry

@@jah2029 You're welcome :)

Here it is but I made the channel with a plyers - Eastwood makes a tool that creates that 90 degree bend perfectly every time : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-e9bjZ_UxtJg.html Eastwood Tool: www.eastwood.com/manual-perfect-panel-prep-tool.html

That's fine if it does because if there is a pin hole or gap, that bit of moisture is going to have a big battle trying to rust through a weld and break through waterproof fiberglass reinforced filler. It can quickly break through primer and paint - I've experienced it and studied it ever since I was in 8th grade (dad was a body man). Always bought junk, drove it for years and years and sold it for more than I bought it for. Next vehicle will be new though - I hope :)

I agree with you on the channel but there are a lot of folks that insist on strictly but welding so I figured I'd show a way to butt weld and metal finish w/o grinding the welds away. It is a bit difficult. As for the braze - I think that is a good solution too but it too has a few disadvantages. Thanks for you input - Jerry

The patch is always bigger than the hole so it would sometimes be frustrating trying to get it behind the panel. I have done it before like that - but half on it was in and the other half out. You could do that if you wanted - no problem just takes a good patch design. You never have to worry about how thick filler is - that's all magazine, TV, internet nonsense. Every body shop across the nation uses filler every day and no one knows it because they use it correctly. Filler is good - it lasts forever if used correctly :)

@@LakesideAutobody Thanks for your prompt reply. I just thought with the patch behind it would reguire less welding and less beating. You could tek screw the panel on then remove each tek and spot weld the holes one by one. Nothing against filler it is wonderful stuff. I really like your videos as they explain everything clearly. As a very old beginner it gives me a lot of confidence. Cheers from Australia.

@@amraceway Hi Bill - I'm glad you like the videos - feel free to ask ?s any time - I answer every day 1-2 times. I might make a video doing what you suggested one day just for those that would like to do it that way. Have a good weekend greetings from Michigan USA - wouldn't mind visiting Australia but sort of scared of all the creatures you have over there :)

True - Even the manufacturers recommend treating after the welding and painting as opposed to treating before with weld through primer. Some are getting away from the weld through idea and treating after.

Yes. That would work - grind the weld down a little bit, tap the seam down and fill with your choice of water proof filler. What doesn't work is butt welding and grinding away at the welds trying to "metal finish" like some magazines and internet articles are telling folks. The metal is too thin and there are too many variables - like low spots that can't be worked out, warped metal, pin holes in the welds, gaps, thin welds, paper thin sheet metal after aggressively grinding, etc.

@@LakesideAutobody If I can get to the back of the panel, I also put a coat of waterproof filler on the backside of the repair. I've redone work where the backside rusted out if it was exposed to water.

@@stevewarren3051 If you can access the back of the panel to seal it, your golden - it'll last forever - no moisture = no rust. Thanks for the comment.

@@LakesideAutobody That's right for the most part. I've seen older polyester filler repairs also fail because the top coating over the repair was compromised by sun or otherwise. If the paint film is damaged, water can intrude into the primer and porous bondo underneath. Back in the day, they told us to always seal body work with epoxy primer before finish priming.

Wow! Thanks so much - can't believe I missed that. I appreciate you letting me know. Have a great week :)

Both are used in bodywork. Body shops in Michigan use a combination of butt, lap, fiber glass, glue etc. You have to go with one that you can know will last and hold up to driving year round in salt. My repairs can be driven in a salt bath and I know they'll hold up - I've watched them for years and asked folks, "How's it holding up?"

@@LakesideAutobody Well let us just look at your welds and see which is better. the butt welds look to require a thin film of skim coat, which is less likely to to crack, your lap and channel welds, need serious filler to hide the different thicknesses. You keep saying in Michigan all the shops use the lap method. I seriously doubt that. So just stop with the Michigan BS. and we won't even go into filling rust holes with fiber glass on steel. Just stop with saying laps and glue and fiber glass are correct repairs and call them for what they are. They are fast easy ways to get a car to look good for maybe 5 years. You do it like that to speed up your work to get the next car in. But just stop with it is the correct way to do the work. because I have worked on cars all my life! My father was a body man, I grew up in a shop. I was taught the correct ways and the fast ways. The two are not the same.

@@mypointofview6056 Filler doesn't crack if applied properly - never had Bondo crack in my life. There are more than 4000 welds in a new vehicle - all lap welds and they last pretty long. Telling folks to only butt weld is absolutely wrong. Would you fix this butt welding? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-36zkc9UQaTs.html The best is to have all methods at your disposal - I use butt, lap and glue - they all have their place if you want to fix absolutely anything that comes in the doors.

Sorry but both are pretty easy - you saw it on the video. I have to use both methods all the time. You can deny the truth that's in the video. With respect, that's why professional body shops use a combination of lap and butt. One thing to remember - there is not one butt weld in a new car :)

@@LakesideAutobody I believe you are correct in your aspect of the business of collision work where its all about knocking jobs out quick and getting the next one in, then I too would just flange lap weld grind, and cave and pave with filler. Most collision vehicles are just being put back together well enough to get back on the road to be hit again and end up in the boneyard anyways in a few years.