1986 Toyota MR2 - an uncontrollable evacuation of the bowels

[Sweetpea]

How come it’s hot all week and then looks dodgy at the weekend when I can go and play? Although, being fair, it was way too hot for me for most of the week. Ah well, crack on old chap, crack on.

Time to get some filler on that repair. I mean, it’s all behind the bumper and can’t be seen but I need the practice!





Rough as a badgers bum. I’m using P38 (because that’s what the car shop of choice had at half past seven when I beetled off to get some). I hadn’t realised how quickly it goes off. I’m getting better at dobbing it on and leaving it alone.

Badgers are quite furry. You’d think they’d have very soft bums.


While I was working on this stuff… Literally three years ago the rear wheel arch looked like this.





It was patched in, not filled, and painted with POR15 to give it some protection.
Now, POR15 is not UV stable so what has 3 years in the sunlight done to it?

Well it doesn’t look shiny anymore.





I probably only put one coat on it.
Looking closely…





It appears to be quite thin in places but it wouldn’t rub off.
I ground it back with the power file. Under it was what appeared to be a fine dusting of rust leading me to think it’s also gone porous. So when they say that POR15 isn’t UV stable, they are serious, it isn’t. But given that I misused the stuff by only using a single coat and not protecting it I’m not at all upset. It’s done exactly what I wanted it to which is to protect the repair for a while until I could finish the job off.
I’ve actually got some exposed POR15 on the front wings that has been there for a lot longer so it’ll be interesting to see how that’s held up.

Anyway, I ground it off and then coated it with Hydrate 80 to deal with any rust in the original panel. That was left to do its thing and then I ground that off too.
The idea is that I’ll have protected any corrosion but the filler will have plenty of keyed steel to bond to without having a Hydrate 80 layer that might allow it to peel off. Is this the correct process? No idea, but you can be sure I’ll let you know if it fails.

This is it with the Hydrate 80 doin’ its thang…





Because the filler was going off pretty quick I could keep filling and sanding.





Some considerable time later and I’ve got the back part nicely filled and am wondering what paint to slap on the top.
Well the ideal plan is to spray epoxy primer on it but it’d take such a piffling amount and I’ve not got clued up with the big spray gun yet. I wonder if I can do it with the air brush?


Only one way to find out. Suck it and see.





It worked well. The epoxy has gone on fairly nicely. The filler underneath isn’t outstanding so I might wind up sanding and painting a few times but as it’s all hidden behind the bumper I’ll probably not go too mad.

I’m having a bit of a dilemma to be honest. There are two options.
1, Filler, epoxy, solvent high build, cellulose colour, clear.
2, Filler, solvent high build, epoxy, cellulose colour, clear.

The first keeps all the two pack stuff together with the solvent stuff on top, the second gets me a better finish before the epoxy goes over. And the epoxy would seal the solvent stuff in. Probably need to let the solvent stuff go off properly before epoxy locks the vapour in.
I suspect half do one thing and half do the other. And it probably doesn’t matter so long as I don’t sand through the epoxy.


One last thing for tonight. Remember I replumbed the compressor with a condenser and drip leg before the water trap? Well there is a big pile of nothing in the water trap so I opened the valve in the bottom of the drip leg and…





Looks like it works then.

James

[blackpopracing]

Always epoxy over primer. everything else on top.

[varelse]

Going to side track for a bit. Mildly.
I made a thing out of metal. I etch primed it.
I bogged some of it over the etch primer.
I then gave it a coat of enamel.

The enamel peeled off the bog.
I didn't think I needed a primer over bog, but apparently I do. So what do I go over it with?
I'm trying to do as few coats and buy as few rattle cans as possible as this thing has cost me more than it would to buy one already, just in consumables.

I have etch primer, plastic primer, and some acrylic primer I think, but not sure if that will work under enamel?
Or is it the other way around?

[Sweetpea]

Jul 25, 2021 21:57:45 GMT blackpopracing said:

Always epoxy over primer. everything else on top.

Thank you!

Jul 26, 2021 1:49:41 GMT varelse said:

Going to side track for a bit. Mildly.
I made a thing out of metal. I etch primed it.
I bogged some of it over the etch primer.
I then gave it a coat of enamel.

The enamel peeled off the bog.
I didn't think I needed a primer over bog, but apparently I do. So what do I go over it with?
I'm trying to do as few coats and buy as few rattle cans as possible as this thing has cost me more than it would to buy one already, just in consumables.

I have etch primer, plastic primer, and some acrylic primer I think, but not sure if that will work under enamel?
Or is it the other way around?

Enamel? You see I looked that up and the word 'enamel' can refer to a few different paint types apparently. This is why I have no idea what I'm talking about. It's confusing and I'm probably over thinking it.
I was going to say that I've never used enamel paint, but guess what... The adhesion promoter (plastic primer) I have has 'enamel' written on the tin.
To be honest I can't see why any particular paint wouldn't stick to filler. Does your enamel stick to anything?



So here is what I think I know. Here's what I think I've decided I know. Here's what I think I've decided I know at the moment but it's likely to change...

For preference, put filler directly on the metal.
You can put filler over epoxy primer (the epoxy protects the steel until you get on with the job). But I'm going to avoid it if I can.
Don't put filler over solvent (rattle can paint for example) and then use solvent over the top. Apparently the solvents in the top layer can soften and lift the feathered edge of the filler by dissolving the paint under the filler.
Some people suggest epoxy (if you really need to), filler, high build, and then epoxy again to seal it all in and give a good base for the colour coats. The more I'm thinking about it the more I like that idea. It feels right. But I'm going to avoid having anything under the filler. (Well, steel maybe. Steel would be nice under the filler.)
I'm using Hydrate 80 as a rust killer but I'm sanding it off so it only sits in the pits and the filler or paint is bonded to the steel rather than sitting on top of it. Again I'm not sure if this is a good plan but I'm thinking I should get the best of both worlds.

But most of all... I think I don't know what I'm talking about!

There'll be more on the subject of etch primers and Hydrate 80 another day. But this time it's stuff I've actually done rather than me second guessing what I've read on the interweb.

James

[blackpopracing]

Ideally epoxy over metal (or sanded back hydrate 80) then filler (over roughed up epoxy). Then epoxy again. Then whatever topcoats you want.

[varelse]

Mm see I don't know what counts as an epoxy primer. Nothing over here (maybe in a paint shop, but they are highly inconvenient) has epoxy on the tin.

Here we have plenty of acrylic paints, and about the same enamel paints.
My understanding is enamel is slightly fiddlier, but is harder wearing.

Primers don't say whether they are one or the other, although from memory I think I saw some enamel ones once.

The thing I have made is not car related, so not super important.
I have a fully acrylic (primer through to clear coat) system for the cressida. But it's too expensive for what I made..

[Sweetpea]

Jul 26, 2021 22:42:53 GMT varelse said:

The thing I have made is not car related

So what have you made?
Or is it embarrassing? In which case I definitely need to know! 

[Sweetpea]

In other news… We’ll be doing the news backwards. So you are getting the ‘dead donkey’ story first and main story later.

The ‘dead donkey’ story today is that I ran out of welding gas. Actually at a fairly convenient time because the welding gas shop was still open. So I pootled off to get a new bottle.
Just round the corner from the welding gas shop is the glass shop. I need a new window for my home made sand blaster so I popped in.

I’d actually called the glass man last Friday and he didn’t have any. Well, not 4mm glass. Apparently there is a bit of a shortage at the moment. And when I say ‘the glass man’ I’d like to point out that he’s not actually made of glass because, well, er, I guess it’d be a bit inconvenient.

Anyway, I popped in today and he still didn’t have any. But he did find an off cut that was just about big enough. So…





Good grief that’s better. The previous bit badly needed changing two years ago but I didn’t get round to it. And then lockdown happened and smokey glass didn’t really seem critical in the grand scheme of things.

This is the old bit…





It’d make a good bathroom window.



So how did I run out of welding gas then? Well, by welding obviously.

This is the back of the fuel filler door.





I can’t do loads of work on the wing and put this back on. Best fix it.
Mark out the bit I need to chop out. Notice it has actually holed all the way through. I knew it had ‘cos the paint had bubbled.





And then cut a new bit to weld back in.





I’ve been dead clever here. The patch is going to be cut from a piece of the old wing. There are 2 reasons for this.

Firstly, the new steel I have is about 1.1mm thick and the filler door is only about 0.8mm. Normally I like the new stuff to be slightly thicker but here it’ll cause an annoying step in the panel so I used a piece of the old wing.

Secondly, because it’s already black I can buzz it in and not bother with painting it.





Nah, only kidding! I took all the paint off.

Oh, by the way, the rust on the frame work was tidied up in the sandblaster.
The back side of the door had been blown over at some point but it hadn’t stuck and was flakey. That got tidied up in the sand blaster too.


Some time later I ran out of gas and had my trip to the shops. Some time after that…





I’ve epoxied the back side and tried to wick paint into the seams now. I’ll grab a photo later. The plan is that now I’ve got a pile of paint onto the frame work I’ll trim the patch down and fold the seam over. A couple of little welds on the seam and it’ll be ready for more epoxy.

James

[varelse]

I was going to say, I'm not sure it'll fit like that..

The thing that is not car related is.. not car related.
Its also gone a bit tits up.
The surface primer I used over the filler didn't like the enamel under it and shrunk all weirdly and looks like some marble effect.
So I rolled with it and gave it another coat of enamel.
Hopefully it'll be finished tomorrow so I'll post a pic when it's done.

Oh, nice work on the car I guess.

[Sweetpea]

Jul 31, 2021 12:31:41 GMT varelse said:

I was going to say, I'm not sure it'll fit like that..

Fair point. It is going to be hard to close with a great lump hanging off the bottom so I folded it under, trimmed it, welded the edges, that sort of stuff.





My test of whether I’ve done a reasonable job is can I get away with a ‘thin skim of filler’. And this my friends, is bob on. Pleased with that.

I decided not to over grind the back side and have a strong but visible repair.





That’s had epoxy and a sand in the photo.
Anyway, I half changed my mind and put a little skim of filler on the back too just to disguise the weld a little. It’ll still be visible but it won’t jump out.


I’ve been doing all the painting with the little air brush. It’s working reasonably well. Very well in fact.
One problem I am having is this…





I don’t know if you can see it but there is.a slightly lumpy finish on the panel. This is very zoomed in. If you look in the right bottom corner you can see sanding scratches in the filler. The little splatters are tiny.
I'm not too worried about this because it flats off as soon as you touch it.

Anyway, when I first start spraying it’s really smooth. But after a while it changes sound and goes spluttery. I’ve also noticed that when I clean the air brush there is paint on the air tip. I think paint is collecting on the end and then blobbing off onto the panel.
Now it’s crossed my mind that because the primer is thick I have the jet wide open. And that moves the paint tip past the centre of the air stream possibly causing paint to hit and collect on the front end of the air brush. When I next set it up for primer I’ll slide the paint tip back in its mounting and see if it fixes my blobby problem.





I was wondering if I should set up outside and work on the car this afternoon. The trouble is…





What’s this lot going to do then? It looked blacker than it does in the photo but it could go past us. It could come right over, promise to rain and do nothing. Or it could wait for me to get myself organised, rain and drive me in again.




I gave up and packed in early. Half an hour later...








Welcome to August in South East England.

James

[varelse]

Backyard is looking nice and jungley

[georgeb]

I know how you feel James. We're in the middle of the Rainy Season, which goes on until November-ish, so we're getting a pretty good monsoon downpour every day. No typhoons hit our bit yet though.

After this, we'll have the Dry Season, followed by the Rainy Season again. Dead simple.

None of this Spring, Summer, Autumn, etc., malarkey to try and remember.

[darrenh]

not shy of a bit of procrastination, but this whole weather roulette several times a day is getting very annoying, and also frequent enough to be apocalyptic

[blackpopracing]

The problem with the paint is the airbush is not suitable for primer. The tip is just too small.
You need a 1.8 tip really for epoxy, but can get away with a 1.2 tip if you over thin it.

[varelse]

Jul 30, 2021 21:27:15 GMT Sweetpea said:

Jul 26, 2021 22:42:53 GMT varelse said:

The thing I have made is not car related

So what have you made?
Or is it embarrassing? In which case I definitely need to know! 

I was making a birthday present for my gf.
We're aiming for practical but amusing this year, what with the reduced funds everyone is working off.

[Sweetpea]

Sorry chaps,

I'm just getting back to this.

Aug 4, 2021 18:32:45 GMT blackpopracing said:

The problem with the paint is the airbush is not suitable for primer. The tip is just too small.
You need a 1.8 tip really for epoxy, but can get away with a 1.2 tip if you over thin it.

Yeah, I couldn't agree more. Especially since I've tried a bit more.
It does work and it's really nice that I can put the paint exactly where I want it. But it is slow and if the air brush doesn't flow, say because the paint is going off in the tip, then you are stuffed and it becomes really annoying.
I need something between the air brush and the devilbiss.

I know this because I've been playing...

[Sweetpea]

PS

Aug 8, 2021 2:00:40 GMT varelse said:

That's cool!

[Sweetpea]

It’s always a good idea to present the story in a nice chronological order. Start at the beginning and work through to the end.

So, consistent with motto of Project Portia - ‘never do it the easy way if a harder, more longwinded way exists’ - we’ll be starting a few days ago, then jumping back a couple of weeks, and then back to the present.


Having got the arch close to being right I realised that it was missing the lower mud flap mount.





I know mud flaps do more to catch mud and rot the car away than they do to protect it, but I think the side skirts need something behind the wheel to balance them.
So I made a new captive nut (stainless steel) and as if by magic…





I had some bother with the weld pool contaminating from the back ‘cos it wasn’t easy to clean. But it came out ok in the end. Penetration isn’t outstanding in places but it’s not going to fall out.



Right, time to try out the Devilbiss spray gun. Way back when I was last playing with the wing I’d Hydrate 80’d the rusty bits that didn’t need cutting out and then given the bare metal a coat of etch primer.
But now I have epoxy primer… And ideally I’d like the epoxy on the steel… So I need to take the etch off…

Now I know what you are thinking, just put the epoxy over the etch.
What’s that motto? Something about doing it the hard way… And anyway, this turned out to be interesting.

So I first tried to remove the etch primer mechanically with a wire brush in the battery drill. Tell you what. Etch primer sticks well. It doesn’t come off easily. This is good, and yet bad since I want to remove it.

My next plan was to attack it with thinners.





It just wiped off.
Well that was expected. Solvent paints just dissolve in the thinners. What was a surprise was just how easily it came off.

Next thing of note is the black primer that replacement panels come covered with. I always wondered if it was any good or if you should take it off. Well it would seem to be pretty good. It’s not a solvent paint and it’s well stuck. That’s good news.

Next is the Hydrate 80. Well that didn’t come off either.





I did wizz it back with the Powerfile though.

And lastly, the seam sealer doesn’t come off either.





In conclusion.
Hydrate 80 and Dynax Seam are pretty tough but paint from squirty tins is rather susceptible to thinners. The last bit I knew but the first bit is quite comforting.



Anyway, now the panel is cleaned up… Some would say, unnecessarily cleaned up… I can mix some epoxy primer and paint it again.
Trouble is the garage is massively dusty and there is no chance of painting in there. And the weather is, let’s say, unpredictable. Actually that’s not fair. Last week, while I had to work to earn pennies to keep Mrs Sweetpea in the poverty to which she has become accustomed, it was lovely outside. And predictably, as soon as I could go out and play, it rained. Not even proper rain that does its thing and goes away, just constant little showers that wouldn’t matter if I was gardening but would make a right mess of paint.

What I need is a spray booth.





Oh baby!
The black does make it quite warm inside but that might be no bad thing with regards to the paint flashing off. And I’ll need to do something about the lighting ‘cos it’s more ‘dingy nightclub’ than ‘well lit spray booth’.
I should be able to assemble it over the back of the car though and keep some of the flies off my paintwork.

A bit of a lack of pictures due to me having my hands full but I grabbed a bit of the old wing that I’d cut off the car and got the spray gun out for the first time ever.





Well that’s not half bad I don’t think.

Flush with the warm feeling of success and hoping that it wasn’t because I’d just wee’d myself or something, I went and mixed some more paint and got the wing out.





So I’ve just painted the bare metal areas and left the original black primer alone. Well I have just proved that the black primer is pretty good stuff.

I know what you are thinking. I’ve painted all the seams where I’ll have to weld. Yeah, I have. I’ll drill holes where I’ll need to plug weld and then clean back the paint around the area. That’ll get some weld through primer on it. That way most of the seam will be nicely protected with epoxy and the welds will be the only bit that isn’t.

Well that’s the plan anyway.


I was so pleased with this that the following day I decided to paint the entire back of the panel. To be honest, mostly for the practice with the gun. I’ve been playing with the fan and fluid controls. Most of the above was done with the fan really tight but it made sense to paint the back of the panel and get some experience with the fan a bit wider.

So it all got scuffed and keyed. And then back in the booth for panel wipe and paint.





While I was at it I did the fuel filler door with the big gun too.


So how did it all turn out? Well the back of the wing is great.





Really pleased with that. It will need a coat of black now. I can’t have grey paint in the boot. And it’ll give me some practice with the black before I start painting the bits that will be seen.

I suppose I could save some money and just clear coat the primer. It’ll look properly modern that way. Nah… I’m not mad keen on the fad for silver cars but I’m totally baffled by the current trend of sending them out in grey primer.


I also painted the filler door with the big gun. This was less successful. Partly because I had it hanging from the roof of the booth and the air from the gun just blew it all over the place. But mostly because I seem to have fish eyes all over it.





OK, so that’s probably silicone contamination, but how? It was sanded and prepped at the same time and in the same way as the back if the wing. But the back of the wing is fine and the door is terrible.
It’s a mystery…


James

[blackpopracing]

Did you panel wipe the fuel door? the contamination is in the door rather than the paint if the wing is good. A good flatting after a wash with soapy water will be ok for another coat.

What air pressure are you using on the big gun? is it gravity feed and an HVLP gun? If so then try it at around 25psi, it wont blow the little bits around as much.

As a little test, after a couple of days try to wipe the epoxy off with thinners on your test panel, see how you manage.......

[dabhand]

Aug 11, 2021 20:49:19 GMT Sweetpea said:

Next thing of note is the black primer that replacement panels come covered with. I always wondered if it was any good or if you should take it off. Well it would seem to be pretty good. It’s not a solvent paint and it’s well stuck. That’s good news.

Isn't it electroplated or something, think I read it somewhere ?
Could be wrong though.

I really like the gazebo idea for a spray booth, I've been thinking of something like that but inside my garage to stop any overspray. Will have to sort some sort of extraction though.
For use in the garden it probably isn't much of an issue is it ?