Questions About Bondo & Detail

[Doubler24]

Hello 405th, I have been poking around all the posts and trying to look at some other projects other members have done and more specifically there Bondo/Detail process.



Currently I am on the Bondo stage and I just had a few questions that maybe I get could some input on with my Mark VI Helmet. I have watched all the videos and tutorials and seen different steps used and different methods. Right now I have been putting Bondo on the areas that really need to be smoothed out, such as the back of the Helmet and the Brim/Visor and I was curious would it be better to keep the layers of bondo light? and not glop it on there and sand the crud out of it? I have been sanding things by hand and was originally going to Wet-Sand but ended up using dry method and started off with 80 grit. I have been sanding for a while with the 80, when should I move on to the 320? then when will I know to move onto the 600-800 grit? I have bondo spot putty, should I be using that after I finish sanding with the 80? then bondo spot putty then go over with 320? I have areas right now that dont seem to be curving or smoothing the way I want them to. My dad said I should be using a mouse sander to speed up the sanding, which sounds like a good idea and then a dremel tool for getting little nicks and crannies for detail in the helmet.



Also I did use the Mud Glassing method (resin+bondo) for the inside of the helmet, and I thought I read somewhere that since I did that I wouldnt need to really bondo anything cuz if I sanded thru the paper it would be smooth when i reached the Rondo?



Thanks 405th for your help, this community rocks!

 

[rockoutloud211]

Umm.. Honestly I would say use light layers.. but they don't have to be like paper thin.

Basically I kept layering and sanding between layers until I got the exact shape I wanted (or as good as it was going to get) then I stepped up to a medium grit sandpaper (180-220) then I used some higher grit (400) that way I had a nice smooth finish of dried bondo putty.



Then You have your end result just minus the primer and paint.

 

[DreadMullet]

lets get some pics up...



if we see what you got, it will be easier to give advise.

 

[Doubler24]

Ill take some pics tonight or tomorrow morning of what I have Bondo'd already

 

[Underdogg13]

Pics please.

 

[BenStreeper]

I was curious would it be better to keep the layers of bondo light?



Yes



I have been sanding for a while with the 80, when should I move on to the 320?



Only after it is smooth enough for spotting putty, and then only after you have applied spotting putty.



then when will I know to move onto the 600-800 grit?



See answer above, lather - rinse - repeat



I have bondo spot putty, should I be using that after I finish sanding with the 80? then bondo spot putty then go over with 320?



Yes, see above two answers



dad said I should be using a mouse sander to speed up the sanding, which sounds like a good idea and then a dremel tool for getting little nicks and crannies for detail in the helmet.



This wisdom will come with age, or a good fortune cookie. Take his advice and head to Walmart. you can get both pieces of equipment for about $70 (with a good amount of accessories)



Also I did use the Mud Glassing method (resin+bondo) for the inside of the helmet, and I thought I read somewhere that since I did that I wouldnt need to really bondo anything cuz if I sanded thru the paper it would be smooth when i reached the Rondo?



Yes, and no. You may need to bondo still, and you may also need to thicken up the rondo inside so that you don't sand through it as well (rookie mistake, always happens). BTW after sanding through the paper you will have "Frumpies" of paper that you will need to sand off with a 600 grit AFTER you have primered the area. Primering the area will make the "Frumpies" easier to remove.





P.S.

Pics sir, Pics

 

[kuruma smash]

auto body is a hobby of mine you only want to use 80 to get it close to where the level you want,then switch to a higher grits. if you use 80 to much you will leave deep scratches in the finish that can be seen in the paint.when i sand i use like 4 to 5 different grits. 80 250 400 800 1000 around that range. once you get to around the 400-800 range is where the best time to use your spot putty for deep gouges and air bubble holes.thats what i found that makes for the best finish but thats just my opinion

 

[haji]

Sometimes its necessary to use large globs of body filler. Depends how big the imperfections are. And usually they end up being in areas you cant easily spread the body filler so you have to build a glob around it. Using a non flexible putty knife/scrapper work very well and you can get them cheaply, (2 dollars or less). Credit cards are terrible, unless your working with really small areas.



Spot putty just doesnt work well at all in my experinces, You apply it in one area, swipe it again to clean the excess but it ends up removing it from the imperfection along with the excess.



How do you know when to go to a lower grit?



Use your 80/heavy grit till the surfaces are even and when its sanded down to your desired shape(that doesnt mean the large scratches that will be left.)



Once you are satisfied. Use a medium grit sanding sponge so it doesnt ruin the shape you already have (they are 1.87 each at my my walmart). It would help if you sanded it with a low grit sponge afterwards.



Now you can use primer to even up the surface. My personal favorite is Latex Primer, cant exactly recall the name. Works excellently and you dont have to use alot. You can get it at walmart. I think it works much better than rust-oleum primer.





You could also primer it after your heavy grit sanding, it will save a little bit but not a substantial amount of sanding





hope i could help

 

[CPU64]

Just a simple tip..

You don't have to rely only on sandpaper to get out excess bondo.

As it starts to harden simple use a razor blade to cut off the excess bondo.. Its really easy to cut while its in the gel stage.

 

[Doubler24]

You guys are incredible thanks for the tips, I won't be home tonight so I will definetly get some pics of tomorrow to show some progress.



Also I'll be heading to Wal-Mart to pickup a dremel tool and a B&D Mouse Sander along with more sand paper.



Thanks again for the tips. Pics tomorrow!