
Undercoating.....
Started by
William Bonsell
, 12-19-2010 11:40 AM
#1
Posted 12-19-2010 11:40 AM

Since the race season doesn't start for another three months and having a lot of time on my hands, I am wondering if removing the sprayed on undercoating is worth it.
Does anyone have any idea as to the weight loss achievable with removing all sound deadening materials from both outside and inside the car? Also, any idea as to the
weight gain from an enamel re-paint from someone like Maaco? Debating whether to repaint the car considering all the red SM's in my area.
Love the new site -----
Bill
Does anyone have any idea as to the weight loss achievable with removing all sound deadening materials from both outside and inside the car? Also, any idea as to the
weight gain from an enamel re-paint from someone like Maaco? Debating whether to repaint the car considering all the red SM's in my area.
Love the new site -----
Bill


#2
Posted 12-19-2010 11:56 AM

Make sure you remove that piece of sound deadening foam on the back of the firewall. It's high and weighs a couple pounds. I've heard the undercoating is not that much weight, and I've always left it on since it's low weight. When dry, paint (exterior) only adds a pound or two. I do sand off the protection coat on the doors when painting.
-bw
-bw
I have an opinion so I must be right




#3
Posted 12-19-2010 12:08 PM

I thought I read somewhere on the old site that a coat of paint is about 10 lbs? I have no experience with this whatsoever, so I may be way off.
Vick
www.volko.com
Black SM/SM2/"Slap Bracelet Throwback" #12 in the Northeast....if the car was made in the early 90's it should look like it.
1.6L forever! Bring on your '99's and '01's!



#4
Posted 12-19-2010 12:35 PM

I was under the impression that undercoating removal is illegal.
-Cy
Supported by LTD Racing
2011 + 2013 NER STU Champion
#5
Posted 12-19-2010 01:12 PM

I've been curious about the weight of paint, too. From this link:
http://www.allbusine...13451801-1.html
It suggests that the average is between 0.2% and 0.5% of vehicle weight total. That would be between 5 and 10 lbs.
Another reference I found (lost the link, sorry) suggests 150g/m2 which is 0.85 ounces / ft2. In rough figures the miata has 120 ft2 of EXTERIOR paint surface. That works out to 6 lbs.
Or...based on this datasheet: http://www.lancopain...mer MP-530 .pdf
46% solids, 9 lbs / gallon (wet) = 4.14 lbs (dry). The datasheet states 450 ft2 / gallon coverage. or 1/4 gallon per coat = 1 lbs/coat (2 mil thick).
Also found this thread:
http://forum.specmia...4177;p=0#000000
over at the old site. Everything seems to line up.
http://www.allbusine...13451801-1.html
It suggests that the average is between 0.2% and 0.5% of vehicle weight total. That would be between 5 and 10 lbs.
Another reference I found (lost the link, sorry) suggests 150g/m2 which is 0.85 ounces / ft2. In rough figures the miata has 120 ft2 of EXTERIOR paint surface. That works out to 6 lbs.
Or...based on this datasheet: http://www.lancopain...mer MP-530 .pdf
46% solids, 9 lbs / gallon (wet) = 4.14 lbs (dry). The datasheet states 450 ft2 / gallon coverage. or 1/4 gallon per coat = 1 lbs/coat (2 mil thick).
Also found this thread:
http://forum.specmia...4177;p=0#000000
over at the old site. Everything seems to line up.
-tch
Build: www.tomhampton.info
video: vimeo.com/tomhampton
Support: X-Factor Racing
I didn't lose, I just got outspent!



#6
Posted 12-19-2010 04:09 PM

I'm guessing Bruces number is more accurate. Doing a whole miata interior and exterior might be a gallon+ but just exterior and door jambs maybe 1/2 to 3/4 gallon. If the old paint is not stripped it's added weight but otherwise mostly a wash. To really split hairs some paints have more solids. And some paints take more coats. Very bright colors, like the 1992 limited factory sun yellow, require a white undercoat, which means more paint.


#7
Posted 12-19-2010 04:30 PM

Randy-
I agree. I don't think the numbers I quoted are in conflict with Bruce.
From the lanco datasheet it seems to work out to 1/2 lbs per mil of added paint solids. If you just sand (remove 1-ish layer of paint), and add another color coat its only a pound or two (at most)...depending on number of coats and final thickness.
The 5-7 lbs is total weight for a complete paint job: primer + color coat(s) + clear coat. Something more akin to what you might do if you were completely changing colors, without stripping the old color(s) first.
I agree. I don't think the numbers I quoted are in conflict with Bruce.
From the lanco datasheet it seems to work out to 1/2 lbs per mil of added paint solids. If you just sand (remove 1-ish layer of paint), and add another color coat its only a pound or two (at most)...depending on number of coats and final thickness.
The 5-7 lbs is total weight for a complete paint job: primer + color coat(s) + clear coat. Something more akin to what you might do if you were completely changing colors, without stripping the old color(s) first.
-tch
Build: www.tomhampton.info
video: vimeo.com/tomhampton
Support: X-Factor Racing
I didn't lose, I just got outspent!



#8
Posted 12-21-2010 01:56 AM

#9
Posted 12-21-2010 09:47 AM

#10
Posted 12-26-2010 01:43 PM

I'll be out this year. Going to need a mop to clean up all the drool from you guys.
#11
Posted 12-26-2010 07:09 PM

Yeah, I'll see it when I believe it
Looking forward to this season. The level of competition just keeps getting tougher.
-bw

Looking forward to this season. The level of competition just keeps getting tougher.
-bw
I have an opinion so I must be right




#12
Posted 01-05-2011 08:36 PM

It is alot of work for little gain. As it is, I have to add ballast to my car to make weight so, I guess one of the factors would be do you need to do it to make weight.
Frank
TnT Racing
SCCA Ohio Valley Region




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