Project: Mongoose

Ok so it's in NO way computer related, but what the hell :p

My 13 year old son, Jack, is a BMX fan and has mentioned, on a couple of occasions, he'd like to
1) Paint his bike
2) Have a bike at my house. (He lives with his mother and is with me 3 days each fortnight)
3) Learn more about fixing bikes.

I asked him if he'd be interested in totally revamping a bike from scratch with me. I used to make 80% of my spending money when I was his age fixing bikes for other people so he's EASILY old enough to know what he's doing...

He said yes so here we go.....

The victim.. A Mongoose Pro Stylist which is substantially older than Jack!! (I can't precisely date it, but I reckon, its probably about 20-25 years old)

The bike has, undeniably, seen better days lol.

And the co-conspirator (who's a little shy because I tried to take a pic of him in overalls and it didn't look "cool" - bloody kids!)

Keep you all posted - this will probably get updated weekly as it is something we're going to do together so will have to wait till he's here wednesday nights and alternate friday/saturdays.

Nice project. Glad to see a solid old piece get brought back to life. I'll be watching this.

We did some math... It's going to cost roughly 1.5x the cost of a new bike to do this properly.....

And we're still doing it lol

And so begins the teardown - can't make an omlette without breaking some eggs and all that....

Starting to lose some parts...

The handlebar clamp will need stripping, painting and new bolts

The handlebar grips didn't survive - had to cut them off

The seatpost clamp will need stripping, painting and a new bolt

Handlebars - again, paintstripper and fresh colour

Jack wants to buy and fit a smaller sprocket so not sure about this - i'll probably refurb it anyway and we can test it before buying something new - assuming we can even find something that'll fit - this ISN'T a new bike, after all

Crank arms will be cleaned up, pedals replaced. The days of big spiked blocks of metal for pedals are long gone - I have a collection of 20 year old dents on my shins to show this is a GOOD idea (if I can get the pedals out - no luck yet....)

The wheels need a good clean and polish - the tyres seem to be in good shape

We're TRYING to keep this tidy and organised - I say trying because neither of us are naturally tidy people lol

And on to the vandalism....

Paintstripper!!!!

MORE paintstripper - first coating didn't get that much off...

A good wash down - any trace of the paintstripper on the parts when its paint time will cause huge problems...

Ready for a good sanding - two treatments with paintstripper didn't quite get rid of every bit of paint. Nothing a little 180 grit won't fix...

Erm, ditto....

That's as far as we got last weekend. I may see if I can spend some time on the bike this weekend on the fiddly bits which will utterly bore Jack, so it's ready to push on a little next week. There are a few small dents in the frame and forks so there may be a little filler work to do...

sweet. I love bike renovation projects. I helped my dad restore one of my grandpa's old beach cruisers (Schwinn, probably from the 60s or 70s, not sure on the date) was a lot of fun. will be watching this!

Put paintstripper on the clamps last night - didn't touch the paint. I'm guessing it must be powdercoated but it really doesn't look like it. More sanding and grinding coming up lol

Quote:

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Originally Posted by slaveofconvention

Put paintstripper on the clamps last night - didn't touch the paint. I'm guessing it must be powdercoated but it really doesn't look like it. More sanding and grinding coming up lol

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YAY for nitromors :banana:
Have you got a hot air gun? might not make it flake off but it'll be hot enough to remove with a soft scraper and wont clog the abrasives so much

Quote:

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Originally Posted by jiggiwiddit

YAY for nitromors :banana:
Have you got a hot air gun? might not make it flake off but it'll be hot enough to remove with a soft scraper and wont clog the abrasives so much

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Somewhere yeah lol - but I also have an air-powered sander which I'm pretty confident will kick it's butt, paint, powdercoat or anodised - it's toast!!! :p

Well it will be if I remember to bring some sanding disks home from work.

As for clogging - that's less of an issue than most realise, if you use a really good quality sanding disk. The ones I use do clog, don't get me wrong, but you just wash them and they're good as new in seconds....

IDN if he'll read this but I hooked Xcom up with some materials from where I work and he was amazed at how long the stuff lasts.... He'll vouch for the gear!

Mini-update. When I'm working on this alone, I'm going to try to stick to the boring or slightly scary parts which will either worry or bore my son. Tonight was bearing removal and cleaning time - yay....

Lots of round parts - hope I can remember how they go back together.... This was my first ever crank disassembly...

And the all important middle bit :p

Crank bearings - couple of these missing - think a new set is in order. If it wasn't, it would be now as I probably damaged them getting them out - righty tighty lefty loosey dammit!

Nice empty crank housing

Nice empty fork housing

That's all folks but maybe some more tomorrow - Jack will be with me and no guitar lesson this week so no excuses - especially not if the weather is anything like it was today!

Just a small update, but it took a long time lol....

Using a combination of a 3" air sander with 320Grit disks (way too fine - was burning through them stupidly quickly), hand sanding with 180grit and a wire wheel attached to a drill, got the frame and forks to this point....

Frame and forks in bare metal

There are two small dents on the frame. Neither of them are anywhere near big enough to compromise the strength of the frame to a significant degree. Gotta do something about those....

Bonda FEW Fine stopper

Took a small amount of the FEW and added a tiny drop of the hardener. Last time I used this, on the car bonnet (hood to you yank types) it went hard way too quickly so I used a lot less hardener. I may well have gone too far the wrong way but it WILL harden - just might take a while....

Small amount of filler, and even smaller amount of hardener

Well mixed and then applied to the two dented areas.

Dents filled

If the weather holds out tomorrow (which apparently it should) I'll hopefully get these repairs sanded down smooth, and then the etch primer applied. The etch has to be overpainted after 2 hours minimum and within 24 maximum, so IF the etch goes on tomorrow, the hi-build primer will also have to go on the same day....

See what tomorrow brings eh?

EDIT: Yeah - I went too far the other way - this stuff should be touch-dry in about 15 mins - after 3 hours it was still utterly soft so I scraped it out and re-did it with more hardener this time - fingers crossed.... X

Yup, another glorious sunny day so onwards and upwards.... Time to get some paint on this thing....

Quick and simple Painting Frame

I wanted to be able to get to every part of the frame in one go, so I put this together using junk laid around the place and the frame I bought a while back to hold up a background sheet for when I was taking review photographs.

Rear Brake mounts masked off

Front Brake Mounts masked off

Almost, but not every bit of metal needs paint. The brake mounts were quickly masked off and the part of the forks which goes inside the frame too. There's be no real harm in any of this getting paint but every coat adds thickness and I need them to still work at the end of this.

Detail Spray Gun

My current weapon of choice. This is a cheap and cheerful mini gravity-fed HVLP spraygun. The only real difference between this and a full size gun is the pot capacity. The small pot is more than big enough for the kind of painting I do so I don't see the point buying a bigger gun yet. I actually have two of these - the other one, in silver, you may see later. I only use that for clearcoating. This blue one is the real worker lol.

On another point, I've been referred to as "The Gentleman Modder" in the past here on TBCS. This is mainly down to the fact that I used to do most of my Modding when I was at work on security, so white long sleeve shirt, tie etc.... Time to blow that name out of the water!!!

And off we go

Spraying spraying spraying

Um, yeah, still spraying

More like beachbum modder!!!

Full Etch-Primed Frame

Aaaaaaaaand we're done. The frame (and forks - photo came out crappy) are now well coated in a good coat of Etch Primer. The Primer I used is actually produced by Manor Coatings and requires equal parts of the Primer, and a specific thinner to be mixed. I probably used, at most, about 250ml when mixed, so about 125ml of each product, on the whole frame and forks. Where I work we sell this stuff for about £16 per litre, so I figure properly etch-priming the whole frame and forks, with a quality etch primer, has actually cost less than £2. Not too shabby.

Mongoose Pro engraving

On the very back of the rear forks, there are the works Mongoose Pro Stamped/etched/engraved. Jack wants to try to keep them so I made sure to go a little easier with the primer on those areas. So far so good - lets just hope the next coat of primer, the 2 or 3 coats of colour and the clear don't end up obscuring them...

More details on the frame

I have about an hour now before I can put the hi-build primer on. The etch requires 2 hours to be overpaintable and MUST be overpainted within 24 so there may be another update later today. Having said that, as I'm going to be covering Grey etch primer with Grey hi-build primer - it probably won't look a lot different after the next stage....

So I went ahead and pushed on a little more. Actually I didn't really have a lot of choice in the matter. The etch primer needs to be overpainted within 24 hours of initial application which meant today as tomorrow I'm at work and I think the neighbours MIGHT object to my 93dB compressor going at 5am if I tried to do it before work.

First things first - prep prep prep...

Soapy water, 600grit Wet n Dry, and a tack cloth

A quick rub down with some 600 grit wet n dry with warm soapy water. You don't need warm water, or soap for that matter, but they both help.... Then a rinse off with the garden hose, and good blast with a blow gun to get the heavy water off, and about 20 minutes of direct sunlight to utterly dry the rest of the job. Follow that with a good wipe down with a slightly damp cloth, then when it's dry again, a once-over with the tack cloth and we're ready for....

Lechler Green Ti Primer/Filler and Activator

This is the best quality primer we sell at the shop where I work. Very high build, 2-pack primer. I mixed up some at the manufacturers recommended ratio, 5 parts primer, 1 part activator and went to work... After about 10 minutes, maybe less, I started having some problems with the spray gun - spitting instead of spraying, paint volume dropping etc. A couple of minutes after that, it quit altogether, and all I could get out of the gun was air... I stripped the paint gun (a scary moment or two as I'd never taken it apart to that degree before) and found that the primer had actually solidified inside the gun. It dries THAT fast.... After about an hour of cleaning swearing, scrubbing and generally getting sunburnt, I mixed up another batch of the paint. This time I used a little less activator, and was a LOT quicker getting it on the frame. A few minutes later and...

Forks in Hi Build primer

Frame in Hi Build primer

Remember those two dents? They are no more....

Area where dent used to be - 1

Area where dent used to be - 2

Between the repairs I did with the Bonda FEW, and the etch then two coats of Hi-Build, they have, as expected, utterly gone.

Oh one other thing.... I mentioned before that my son wants to try to preserve the Mongoose Pro lettering on the back of the bike, so a slightly different approach was required. Before I started with the Hi Build, I used some basic aerosol primer on those areas. The quality isn't as good but I had no doubt at all that the Ti Primer would utterly obliterate the lettering. I then made a point of not getting the Ti on the letters, instead fading it out as I got to that area. Here's hoping it looks ok after it's all been sanded down.

Two-tone primer baby!!!

This is supposed to be a collaboration between myself and my son, so I'm on a down-tools now until he's next able to help with it. This wednesday is Guitar lesson so it may be next weekend or even the following wednesday before there's any more progress....

Until then....

Little experiement with the colour...

This is a coarse silver groundcoat, with several coats of semi-transparent hi-pearl purple. Quick and dirty job - no sanding or prep - I just wanted an idea of how it'd look. It looks absolutely stunning in direct sunlight because there is some next-generation xyrillic pearl in there....

I'll try to get a better pic in the daylight soon....

If anything, I don't think the purple is quite transparent enough - I'd prefer it to take more coats to get to the colour I want - the effect will be much deeper that way...

Ooooooooooo pretty color!!!

bumpdate

LOL - I need to re-prime this because I went a little too far when I rubbed it down. Only problem is, I also killed a spraygun priming it up the first time so I need to buy a new one with a bigger needle before I can get back to it - hopefully soon (ish)

That colour looks awesome! The bike will certainly be eye-catching with that paintjob!

any done pictures of that, did you shoot the color over a black.. that will give you a more dramatic look on the pearl

Might be getting passed on without being completed. My son has lost interest in the project and the guy who is letting me use his paint booth is looking for a bike project for his son. Real shame because I was really looking forward to seeing that paint on something other than a test card.

I'll have a word with Steve and see if I can get some pics of it when it is done - but I can't promise anything unfortunately

I love BMX's, this is an awesome thread.

I want to sugjest a pro comp sprocket and chain set, looks mean as hell and the chain will almost never fall off even if its looser than the $2 hookers downtown. Plus the chains are for lawnmowers and are rated to 20HP or something crazy like that.

You need to get a 2 piece sprocket set with an extra outter ring. Double stack the outter rings. Ditch the BMX single stage sprocket screws and find a mountain bike tripple stage sprocket set and use the screws from that. They have deeper thread guides on the nuts and longer threads on the screws. Then go down to the mower shop and get the appropriate length of chain. The rear sprocket has a chain race build into it that is wide enuff that the chain will slide from side to side but will remain on the chain race. The chain is really beefy and cant flex enuff to fall off the race.


Depending how easily you can get the 2 piece sprockets it shouldnt cost more than $20, Looks fly, and the chain will never break or fall off.

Double stack the outter ring