17 replies to this topic

[madtoranajzedded]

Hi guys.. silly question can you apply bog
over bog while the first coat is tacky.or
do you wipe that tackiness off that some
filler has with thinners ,wax&grease.im using
3M plus.

Im asking this as if say i dont get enough on
or it starts drying before i can apply the
rest as i think sanding then applying epoxy
Scuffing again then applying more bog is a
stuff around...i can see why crash shops
apply it on metal as it cuts out the waiting
etc..if i get the bog on smooth enough then
Applying more in say within 15min that should
Work?.. what you guys reckon...

Cheers maz

[fx48_eh64]

more bog  love that phrase, apply more bog lol

[sibhs]

Bog on bog is fine.  

 

As you know I'm no expert Maz but I'd bog then coarse sand/shape before bog goes rock hard, then bog again if required.

 

Bog

Sand

Repeat

 

Marty

[Rockoz]

Better off bogging then sanding/filing/shaping to get it as close as required.

Then put some more bog where required.

If you just slap some more on the top with out at least doing basic shaping it will become a shit fight.

You will end up with heaps more bog where you dont need it.

And worse you will end up with lots of air gaps in the bog if it isnt smooth before the next layer.

Most bog jobs require a few layers, as many as it takes to get it right

[TerrA LX]

Whats tacky?
I would be letting anything set before reapplying...
Wax and grease maybe if needed but thinners is way too strong.

[71xu1]

Big no no applying bog over bog without first removing all of the tackiness. You will have no end of trouble down the track. Rough out with a cheesefile or body file blade, shape further with 36 grit, clean off all dust reapply bog and sand away again. 

[madtoranajzedded]

Thanks for the replies..dammit..too late 😞
I went ahead and applied it over the tacky
body filler.i dont think i put enough hardener
when mixing .its hard to get it right.its like
35+ in shed so ive tried using less hardener.
The areas i done i had to mix and have it on about 3 minutes.maybe a little longer.the
tacky area it feels a little cheesy.just
trying to give myself time to apply it.havnt
played around with body filler for yonks and
couple times i applied it good for all but a little area then tried to apply some there and
made a mess of it haha.

I will take it back out on the orbital nxt
week..ive actually ran out of epoxy and new
tin wont arrive till nxt week hence me trying
to get away without sanding and exposing the
bare metal.

[Bigfella237]

35° in Southern Tazzy... holy crap! I thought you could throw a rock and hit the ice cap from there?

 

You need to make sure the previous application is fully set before applying more. If you added too little hardener it will either take a long time to go off or won't harden at all, and if that's the case you're wasting your time adding more on top as the non-hardened layer will need to come back out altogether.

 

Temperature (both ambient and panel temp) does make some difference but essentially bog is chemically hardening. Without enough hardener it will just never set properly and no matter how many properly-set layers you put over the top, you'll have no end of dramas shaping it and probably great chunks of bog actually falling off the car later on, paint 'n all!

 

If you need to apply more than one skim without shaping in between then it sounds like you're trying to fix something too serious and should really be working the panel further first. IMHO bog should end up millimeters thick, not inches, that's not to say that I haven't seen guys virtually forming new panels with the stuff though.

 

Likewise if you sand through to metal in one spot but still need to add bog elsewhere, you probably need to address the high spot rather then continue filling the lows. And how do you know where to apply more filler if you don't at least rough the shape of the panel out first?

 

As for sealing off the exposed metal areas, I guess it depends on the job? If you're able to finish working the panel entirely, then just Epotech over the whole lot in one go and you're done ready for polyester. But if you still have more work to do then you'll likely sand back through it again anyway.

 

[TerrA LX]

Im with the bigfella, when you remove what you have applied, have a good look at the repair, bog is meant for a skim, not a filler...

[StephenSLR]

If you added too little hardener it will either take a long time to go off or won't harden at all.

 

Without enough hardener it will just never set properly and no matter how many properly-set layers you put over the top, you'll have no end of dramas shaping it and probably great chunks of bog actually falling off the car later on, paint 'n all!

 

Yep, a chemical reaction occurs between the two chemicals you mix. If you don't mix the right amounts of each you won't get the end product right.

 

Imagine drinking cordial and for whatever reason you add more or less water, it's not going to taste the same is it?

 

If the conditions in the shed aren't right, you'll have to do it elsewhere or wait for the right time, see the manufacturer's recommendation if there's an ideal temperature range.

 

 

If you need to apply more than one skim without shaping in between then it sounds like you're trying to fix something too serious and should really be working the panel further first. IMHO bog should end up millimetres thick, not inches

 

Exactly.

 

That's why you pay a panel beater; to form, shape & beat panels, otherwise they'd be called bog slappers. lol.

 

Don't ruin your car with heaps of bog, get the panels right first. Ideally the bog is there as a light skim coat and you should be sanding most of it off.

 

s

Edited by StephenSLR, 19 January 2018 - 07:57 AM.

[Shiney005]

Bomber the Bog Slapper.  It has a ring to it.

[Rockoz]

Trick is to mix smaller quantities.

Use the same amount of hardener, and if it starts going off throw while you are putting it on just stop and throw the rest of that mix out.

Bog is cheap. If it takes 10 applications to get it where you want then it takes 10 applications.

Bog is the shortcut. Dont try to shortcut the shortcut.

[madtoranajzedded]

The 2 areas are in engine bay.one is where ive
welded up holes where heater box was and the other was to the right of where the generator
voltage regulator was on the lhs of inner
guard i cut out the rectangle ridge what
Regulator bolted to and to the right of it is
a depression bout 3 1/2 round and roughly 2
1/2 mm deep ,maybe a tad more.but on further
examining i laid the spring steel spreader
horizontal and is under a mm.thats with the
filler in there but vertical its a near 3 and
goes all the way to front like that.i only
wanted to fill in a little so its less
noticable.ive noticed with the filler being
tacky on top it gums up the paper but once
That thin top layer is off it doesnt gum up
at all so it must b just the resin in filler
Coming to top ..i think i need more prac
When laying it and i think im spreading it
too much and end up with a bigger area to sand
than required..

She has had a hit on lhs front guard so maybe
thats the reason for the dip right along.

They say with bog it can fall out the day you
do it or could last 20 years.

[StephenSLR]

They say with bog it can fall out the day you do it or could last 20 years.

 

I'm guessing that has to do with how it was mixed, applied, how well the area it was slapped on was prepared, how thick it is, etc.

 

You also have to leave it a certain time to harden and breathe before applying paint on it too.

 

s

 

 

[madtoranajzedded]

I gave that inner guard a hit with a dolly
from under guard and it went pong..thought
you beauty its gone but it buckled the other
way but not as bad.put a bit of a dent in it
when i hit it..the panel has the oil can
affect.what i want to know is how hot do i
get the panel before apply a rag..ill b happy
to get 50% out .the worst is where ive sanded
a little it gets less as it moves toward
front..

 20180305_162749.jpg   113.32K   6 downloads

[EunUCh]

Find roughly the center of the oil can area , mark a circle with chalk , you will need a wooden mallet with a rounded off end and a flat dolly.

You don't need too much heat , a propane burner type thing is plenty , it is easier if you have someone help by gently heating the area while you hold

the dolly behind the area , you will see the area move almost straight away when the heat is applied , best to have it rise toward you , soon as it rises a bit

gently draw the metal towards the center of the circle all around the circle , no need to flog shit out of it , once you have drawn the metal tap the center

of the circle to slightly flatten it then quench with wet rag....worked for me , sometimes you might need to chase it once it has been plenished.???

[grumpy xu1]

All really good replies to Maz, depending on the size of the oil can, you may even be able to heat & quench straight away & it be tight. Maximum thickness of bog should be no more than 6 mm deep, preferably under 2 mm. Try varying the pressure you put on the applicator, that will dictate the amount you will apply to the area, softer = more, harder = less, the more you do that, the better you'll become at it, traditionally mixing in a figure 8 patern, gets a more consistent mix & eliminates air bubbles. Not many people teach that now.