T4 : Battle Across Time (2010 to present)

[regcheeseman]

Often wondered why the ole chap never sanded filler wet.What will they think of next.

Yep, UPOL easy sand is a fecker for swelling up and shrinking back.

oh and pinholes - it likes those too.

[Hans]

Getting confused here, 2k primer first, no filler first, epoxy filler, no not . Dry? wet?
I hope i am not miles out.
2k epoxy filler/putty direct on metal roughen up with 40 grit for the first couple of layers. Is not easy to sand, but no shrinkage and moisture resistant, got build in anti corrosion properties
Then a 2k epoxy primer and a easy sand filler for the smaller bits.
And from that as Reg said, high build 2k filler/primer and so on

Sent from my SM-G930F using Just T4s

[Activ8]

It's not the advice that's confusing Hans, it's the job to be tackled. Arguably each aspect of the work has very different requirements. Understanding the products is key to building up a protected, long lasting layered finish.

Not one "process" covers it all - however one elongated philosophy does. Do it right first time, take your time, invest in good products and read the tech specs NOT the tin instructions! Oh and listen to Reg he speak truth albeit he needs updating with the latest Upol products.

I'd recommend in my apprenticeship status to download and read the tech spec sheets. You get an order of works, kit required, timings - really good guide. Don't buy in large quantities unless you're going to use it. UPol site is a great start.

[Activ8]

Did some more yesterday on the gurt fannies bonnet. I'm taking my time because I've found it confusingly new and incredibly technical in a bodywork sort of way.

So, after studying the bonnets lightly sanded & filled "clouds" I arrived at the thinking that no more filler was needed but a larger sanding block, dry 400 grit and a little more elbow effort took down the slightest peak of the filler to produce what I considered was a smoother flatter feel.

Keen to do a good job I applied another two cans of Upol grey primer.
One can will cover the bonnet twice with two 0.03mm layers about the depth of one human hair!
Although recent posts might query that fact.




The tech specs advise sanding to use a dry 400-600 grit, and 600-800 wet. Reg advised dry which made sense to me yesterday and then with todays previous posts.
Once with dry 400 then dry 600 every stroke raised my job satisfaction index. I had no 800 but I've ordered a broader selection of grits to experiment with.

In for a penny ... I've decided to stay with the Upol Satin Black paint colour in a rattle if only to test whats possible for this apprentice!
One can will cover the bonnet with a single layer of just 0.01mm, so following the guide I dusted over the bonnet several times spacing the coats every 20 minutes.





Thats one can gone, its a very very fine layer of paint - understandable what Reg implied by the volume of paint and using a HVLP gun to deliver a better result!
Not bad really - well for this apprentice.

Now I should of just stopped there and continued another day as it was my birthday and the evening involved drinking, some Zooming and a few distanced visitors BUT I'd left the bonnet out, thinking I could get another can/coats on during the afternoon and evening. Errrr - by 9pm I was covered in black satin paint , god knows what the bonnet looks like (I'm reluctant to actually look), its rained overnight and I'm red raw after scrubbing off Upol. Mrs is not speaking to me - so something positive during the hangover phase!

Possible updates to follow.

[regcheeseman]

Guide coat as per first picture, any more is just extra sanding (much like your filler work)

How did you work out your coverage.... can volume divided by bonnet area?

[Activ8]

Guide coat as per first picture, any more is just extra sanding (much like your filler work)

How did you work out your coverage.... can volume divided by bonnet area?

Well thats where the experience kicks in, plus I was taking the piss when I smothered it with filler (that day I could spare the time removing it).
Yep, coverage from tech specs per can divided by bonnet area + a % margin for over spray & an allowance for spraying myself!

[Activ8]

Hmmm , looks like some sort of reaction .

Better get the sanding block back out and some 600?

[mike_skinner]

Doesn't wet sanding make the filler shrink, I thought it made the filler soak up the water, expand and then sink as it dries or is it ok on the final sand?

bloke I used to work with was timeserved bodyshop - I did a bike fuel tank under his guidance - big dent and a crease = bare metal the area, fill sand fill sand fill sand fill then final sand wet after sanding through the grades up to 1500. Left for a couple of days in the house to dry then prime and paint. You couldn't feel the repair prior to paint. I've done one rear arch wet (but only up to 600) and the other dry as I was getting sick of my life so see what happens.

[mike_skinner]

Hmmm , looks like some sort of reaction .

sweat droplets from the excitement of painting? Rain?

if its a reaction you need barcoat

[Activ8]

sweat droplets from the excitement of painting? Rain?

if its a reaction you need barcoat

I think the can nozzle went fubar under the frivolities plus there's a few deep dents where it was lobbed at me - probably!
Got the paper & block out and had a therapeutic 30-40 minutes in pure silence.

[Jumbungla]

Really like reading these posts Rob, I know what you mean about the technicality of it all. I've not used any filler yet, trying to avoid it as much as possible.

Happy birthday by the way! Sounds like it was a good one.

Sent from my SM-N950F using Just T4s

[regcheeseman]

Better get the sanding block back out and some 600?

Tiniest spot of filler in that square hole? Then prime around that badly feathered eye, flat, prime, flat, prime, flat, prime - a polythene plastic bag or glove can help you feel the surface better than bare fingers.

[Activ8]

Tiniest spot of filler in that square hole? Then prime around that badly feathered eye, flat, prime, flat, prime, flat, prime - a polythene plastic bag or glove can help you feel the surface better than bare fingers.

Thanks. I'll try that.

[Activ8]

Tickling the electric turbo along. So needed to understand the spindle speed required to generate sufficient boost,
Cleaned up the GT1544 (its actually a 1.9TD turbo) so 32.9/43.9mm compressor wheel.
Here's the Compressor Map.

If I can get the electric motor to run a controlled 180k rpm it'll generate 1 bar & will add 100bhp (with the additional fueling) very early in the Greddys larger turbos boost curve.
My Greddy turbo can only boost 6psi at 2000rpm , it runs 85bhp 225ftlb at 2k rpm (AFR 15:1) and 150bhp 316ftlb needs more boosted air.
I've got the AJT's map to allow boost through the EGR between 1300and 2300rpm.
I'm hoping to get Fruitbat to machine a new snail back plate, fixings to hold the motor to it, bearing seal with an engine bay mounting.
The compressor wheel will be balanced directly on the motors armature.

[regcheeseman]

Is it safe to add that much boost that low down, is that not the point of the torque map.

Or is the plan to run a huge turbo and let this fill the void?