shrinking issues.

H

Hotbo

I have always had some what of shrinking issues on my bodywork( i do collision repair and have repeat customers).as of late it has gotten worse than normal(over the past year).i have used SPI 6401 2k sealer/primer for years as my mine primer/sealer.i use it 4-1 for all my prime work and 4-1-1 or 1.5 reducer for my sealer let it flash,tack,base,ect.
i have a Sherwin Williams ultra 7000 mix bank and i also use Pro Spray base(bout equal which one i use).i have used many different kinds of filler over the past 24 years.i have switched about 2 years ago to either Keystones cheap filler or 3m lower line filler.just as a reference i have used the high end lines of filler(evercoat gold) 3m Platinum plus.i have seen shrinking in all the different brands. i refuse to pay 50 dollars for a gallon of filler so i went with the cheaper lines(i can get them 12-14 a gallon by the case).
i used Sherwin clear and SPI 2100 clear or UV clear.
so what in your opinion is going on?cheap filler? need to use different primer? both the bases shrink equally...
when i say shrink i can see all my sand lines,inline 80 grit marks and sometimes a halo around the entire area which i call the starburst affect,lol!!!i dont go past 80 on my finish work of filler.thanks for any feedback.Travis
 
First thing I would do is try another primer. The SPI Turbo is excellent. Do you observe proper flash times? Are you letting it cure completely? Most of the time something like you are experiencing happens because you are piling on the primer, or not observing proper flash times, sanding it before it is cured etc. I'm thinking you are laying down really heavy coats and not letting it cure completely. Another thing I would change is to finish your filler/glaze with 180 grit. That alone will help alot.
 
all of the above could be accurate.i rush b/c most of my collision work is on a tight schedule.in the winter i can see what your saying to be even more true.i have thought about these things as well.
for the past 3 months its been pretty warm to down right hot in western Arkansas.my panel temps for the past month during work hours stay above 80-90.i do my bodywork then prime.generally wait 6-8 hours before first block(that can be same day to next day times.)block my primer with 180 wet and lay 2-3 coats of primer after that.i finish block with 400 wet.if i have to paint the same day i wait at least 2 hours with panel temps well above 70 degress.i do my paint work.next morning i un wrap car and look for areas that need buffed or my repair areas.9-10 times my repair areas already have what i call mapping...

Flash times may cause some issues i guess? i use no reducer in my primer if that matters,thanks Travis
 
Always feather the area before repairs with 80 then 180grt. Do your repairs and stop with 80grt blocking, I then feather again with 180 to remove 80grt scratches in the previously feathered area and skim the entire area with Icing poly filler then block sand with 180grt, sand the outside area with 320grt and prime allow proper flash and apply another coat, if you do 3 coats then allow to flash and go for 3. Allow that to dry for a couple hours or over night, sand primed with 320 or wet sand (whichever you choose) and reprime, allow to dry and get it ready to paint. If you can heat lamp the primed area before the reprime this helps make sure that it is good and dry. Bullseyes can be troublesome but when you can do a reprime before final prep and paint the likely hood of them and the sand scratches showing is greatly reduced.
 
Rush mentality will always run danger of shrinkage, always. There are many ways to minimize the problem, but the best way is time. But shops are forced to do the "cycle time" dance and quality is always the victim. I've eliminated or drastically reduced visible shrinkage in our repairs, but it takes many procedures that don't fit well into the standard collision shop mentality.
 
these guys are right. no urethane primer can be expected to fill 80 grit scratches and not shrink back into them. 80 grit is far too coarse. you need a 180 grit finish or finer on your filler.
 
1. Customers have to be educated on the reasons their bumper can't be fixed and painted in the same day, etc. When management is trained to explain procedures to customers and the pitfalls of going too fast, customers nearly always accept the fact that more time is needed. Insurance companies hate that, but personally, I don't care. I don't work for them, I work for my customers. If there is parking space in the lot, letting primer dry while other things get done does not impact efficiency like industry shills would have you believe. It increases quality and reduces comebacks at the expense of the holy "cycle time" the insurers use as a whip to speed shops along.

2. Portions of the repair that need primer should be put into the prep bay as soon as possible. Jobs should be orchestrated so when the bodywork is done, primer follows within hours. This maximizes cure time.

3. Don't use cheap filler except as a first coat! It is too porous and absorbs solvents. It needs to be covered entirely by a high quality polyester putty.

4. Sand as fine as possible. The coarsest we ever leave bodywork is 180 that has been smoothed slightly with 220. Many times this gets carried out to 320. Exposing a slight high spot is a small price for having smoother work. Nobody will notice the high spot, they will notice dullness and scratches. Where putty rides up onto paint featheredges, first the featheredge must be 220DA or finer before putty, and the area where the paint and putty meet should be blocked with 320 until all the rougher scratches are out of the paint. This is usually where shrinkage can be worst, linear scratches that are left in the paint featheredge.

5. Don't primer and paint on the same day. It's not good, period. It's better to pay a little overtime to have the primer put on the night before, than to rush, force dry, and paint in the same day. In the long run, the OT is nothing compared to the risk of redos and damage to the the shop's reputation.

6. Don't abuse material. Urethane primers need to be kept to 3 coats max per priming session. If the work is not good enough to be smoothed out with 3 coats, it needed another coat of putty. If there's just no choice but to put on more primer, it needs to wait until the next day, period.

7. Last but not least, proper flash times, of course. Set a timer. Every cell phone has one, now.
 
thanks guys! i feather all repairs with 180.i do not use any kind of icing or putty.i finish with 80 and then feather with 180.i have never had a single customer complain about my repair areas.i just see them and wonder how to minimize this.everyone has pointed out excellent tips i skip due to cycle times!after years and years of doing this over and over i have become robotic... i see every blemish and quick to point out other shops shoddy work when my own seems to fall in that category after some time.i never have to block my bodywork with Primer more than once.i never prime something that needs more filler to cover bad body work.i am thinking i need to finish with finer grit then 80.Thanks Travis
 
Thank you again everyone! i am going to can the cheap filler and start using some polyester to finish with and a finer grit...gonna get some Turbo spi in the morning and maybe that will help as well.
 
crashtech;n84052 said:
Rush mentality will always run danger of shrinkage, always. There are many ways to minimize the problem, but the best way is time. But shops are forced to do the "cycle time" dance and quality is always the victim. I've eliminated or drastically reduced visible shrinkage in our repairs, but it takes many procedures that don't fit well into the standard collision shop mentality.
Click to expand...

crash you are correct.i am a small shop that i took over from my Dad that he has had it since the late 60s.i started with him in 95 and bought him out in 05.we have a good solid customer base(he still helps me a lot but is 71 years old).i am way to rushed trying to push jobs out and working crazy hours to get them out(just me and him).i will try to slow down and do some additional steps to help my repair areas,thanks as always Travis
 
what filler would you guys recommend?? what icing or polyester would you use,thanks Travis
 
Check with your jobber that carries Evercoat products about the Evercoat Edge line. The "Edge Premium" filler is the same as Rage Ultra but cheaper. If not that try some Rage Ultra. Sands great.
 
Chris_Hamilton;n84062 said:
Check with your jobber that carries Evercoat products about the Evercoat Edge line. The "Edge Premium" filler is the same as Rage Ultra but cheaper. If not that try some Rage Ultra. Sands great.
Click to expand...

what is a good Part# for this filler? i have tried to find it but coming up with conflicting #s.thanks Travis
 
9 times out of 10, when this happens, it can be stopped with two little changes.
(not counting as a change but epoxy over the cheap filler will also stop this)
First coat of primer spray a wet coat and flash it good, as trapping solvent in first coat will swell scratches and very common when 2nd coat apllied to fast.
The solvents can make a 320 grit look like 80 if bad enough.
Being old school, I always finish filler with 80 grit but than again, I'm using epoxy over the filler before primer.
In rare cases where i did not use epoxy, I let first coat of primer set for 10-15 minutes before second coat, third coat does not need that kind of flash but first coat just like a basecoat causes the most issues as far as solvent trapping.
Cheap filler needs to go and best buys are in the $26-32 range such as Marson gold, platinum or Z-grip.
 
crashtech said:
Rush mentality will always run danger of shrinkage, always. There are many ways to minimize the problem, but the best way is time. But shops are forced to do the "cycle time" dance and quality is always the victim. I've eliminated or drastically reduced visible shrinkage in our repairs, but it takes many procedures that don't fit well into the standard collision shop mentality.
Click to expand...
Yep.. Can't rush things
 
Barry said:
9 times out of 10, when this happens, it can be stopped with two little changes.
(not counting as a change but epoxy over the cheap filler will also stop this)
First coat of primer spray a wet coat and flash it good, as trapping solvent in first coat will swell scratches and very common when 2nd coat apllied to fast.
The solvents can make a 320 grit look like 80 if bad enough.
Being old school, I always finish filler with 80 grit but than again, I'm using epoxy over the filler before primer.
In rare cases where i did not use epoxy, I let first coat of primer set for 10-15 minutes before second coat, third coat does not need that kind of flash but first coat just like a basecoat causes the most issues as far as solvent trapping.
Cheap filler needs to go and best buys are in the $26-32 range such as Marson gold, platinum or Z-grip.
Click to expand...
I can still get Z-grip at a good price but Platinum has jumped in my area, over $40 for anything decent. they seem to have 10 price increases in a year. Can't keep up with them. lol
 
I know this won't fit your schedule but I always put down one coat of epoxy, wait until next day and then lightly sand and apply 3 coats of 2k. That epoxy barrier has done wonders. It may not fit for every project but if you get that one in there that has to be right, it's well worth doing.
 
Chad.S;n84069 said:
I know this won't fit your schedule but I always put down one coat of epoxy, wait until next day and then lightly sand and apply 3 coats of 2k. That epoxy barrier has done wonders. It may not fit for every project but if you get that one in there that has to be right, it's well worth doing.
Click to expand...

i have done this on no rush jobs.it does help a lot.Barry i was taught Body work by my dad many years ago and he finished everything with 80 and primed.like you said old school,lol!!!
 
Barry said:
9 times out of 10, when this happens, it can be stopped with two little changes.
(not counting as a change but epoxy over the cheap filler will also stop this)
First coat of primer spray a wet coat and flash it good, as trapping solvent in first coat will swell scratches and very common when 2nd coat apllied to fast.
The solvents can make a 320 grit look like 80 if bad enough.
Being old school, I always finish filler with 80 grit but than again, I'm using epoxy over the filler before primer.
In rare cases where i did not use epoxy, I let first coat of primer set for 10-15 minutes before second coat, third coat does not need that kind of flash but first coat just like a basecoat causes the most issues as far as solvent trapping.
Cheap filler needs to go and best buys are in the $26-32 range such as Marson gold, platinum or Z-grip.
Click to expand...
i have tried Z-Grip in the past and didn't care for it.Dad always used evercoat Rage but i hated growing up using it! sanded like concrete...
i can get the Evercoat edge Premium #200522 for 38 a gallon gonna give it a whirl.Travis
 
I don't do insurance work, but I am a firm believer in epoxy before and after the repair. It took a while to undo putty over bare metal and put over epoxy , but this forum helped me change. I also 80 grit, shoot one coat of epoxy and then shoot turbo the next day. 2 coats block with 320 wet and respray 1 coat and then 400 wet for solids and 600 wet for metallic's. I'm usually stuck with axalta, but have been lucky to have shot a lot of spi black lately. UV for clear. Block and buff next day. No heated booth. No shrinkage either.
 
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