Fiberglass Bumper Moulds attempt

[andyverran]

Afternoon all...

Decided, since I was off to Devon on Thursday, I'd have a bash at moulding the bumper quarter before I went.

Many, many errors here...I really didn't expect it to work first time (and I wasn't disappointed), though you always hope a bit don't you!

Think I need to use something "clay like" to get a better edge on the mould, and more layers of glass, leave the PVA for longer to dry and have more layers of that.

Really struggled to get anything to act as an edge to the bumper...

Gel coat was to thin as well...

Some bumper got stuck to it to boot...fingers crossed it lasts through another go...

Attempt no 2 when I get back I guess, after another pay day

If anyone has any suggestions on how to do better or pointers for cheap materials please chip in.

Oh, I weighed the original part (3.5Kg) and the mould attempt...497g so if I can get it to work the final bit may come in at 1Kg if I'm lucky.

[sjoe]

remove all the loose material from the bumper, and fill the holes with body filler, the smoother the surface of the bumper is the better so sand back any rust and get it all really clean.
then wax the bumper, the more coats of wax you put on the better it will stop the gel coat grabbing the bumper.
you can use tack-free aditive with the gel coat and that should help too.

apply a couple of thick coats of gel coat and just before the gel coat has set completely hard start to apply the fibreglass, the more coats of glass you put on the better especially if you plan on using the mould multiple times.

good luck, making moulds from rusty stuff is always gonna be diffucult

[shokenore]

Pva?

[andyverran]

remove all the loose material from the bumper, and fill the holes with body filler, the smoother the surface of the bumper is the better so sand back any rust and get it all really clean.
then wax the bumper, the more coats of wax you put on the better it will stop the gel coat grabbing the bumper.
you can use tack-free aditive with the gel coat and that should help too.

apply a couple of thick coats of gel coat and just before the gel coat has set completely hard start to apply the fibreglass, the more coats of glass you put on the better especially if you plan on using the mould multiple times.

good luck, making moulds from rusty stuff is always gonna be diffucult

tack-free aditive is a new one on me...I'll check it out.
I did wax but not enough I think...hurrying a bit to. Same with the gel coat, to thin and added glass to soon...

I'm only after one use of the mould, just to replace the part, those bumpers are far to knackered to use the mould for anything else...it may not be obvious from the pics but they're also a bit bent.

lol, if i sand back all the rust there won't be anything left.

[andyverran]

Pva?

I'm never going to be able to spell that!

so cut n paste -

PVA (Polyvinyl alcohol)

[sjoe]

haha, just back any holes you make with bridger and then use body filler to give a nice smooth surface, also use a really fine sand paper over the whole thing before putting the wax on.

[andyverran]

haha, just back any holes you make with bridger and then use body filler to give a nice smooth surface, also use a really fine sand paper over the whole thing before putting the wax on.

OK...take 2 in a week or so. ..thanks for the input.

[shokenore]

It seemed so simple to me.
I used to watch my Uncle make whole frickin boats out of the stuff!!!
Ok so he had a fully equipped boat yard and molds....
I will post up my very lame attempt when I'm back from Kernow.

But like you I want to at least try to get it to work.

[andyverran]

It seemed so simple to me.
I used to watch my Uncle make whole frickin boats out of the stuff!!!
Ok so he had a fully equipped boat yard and molds....
I will post up my very lame attempt when I'm back from Kernow.

But like you I want to at least try to get it to work.

Man Vs Glass...

[shokenore]

Man Vs Glass...

Indeed.
I wonder if bagged expanding foam might be worth investigating?

[andyverran]

Indeed.
I wonder if bagged expanding foam might be worth investigating?

Mmm...always worth a look....if you find any good links while I'm away pop em on here, I might get some some quality time with my phone you never know.

haha, just back any holes you make with bridger and then use body filler to give a nice smooth surface, also use a really fine sand paper over the whole thing before putting the wax on.

Filled, rubbed and generally fiddled about with....ready for when I get back.

[andyverran]

well...made a little progress on fiberglass bumbers (3 of the 4 bits kinda ok enough to use...), but hit a terminal snag...never going to get a mold from that bracket!

Taking it all off has sorted the droopy suspension though :-)

[shokenore]

Like it

I started with something not quite so visible.

What is the device in the top left of the first pic?

[andyverran]

Like it

I started with something not quite so visible.

What is the device in the top left of the first pic?

e-ciggy...big battery and can charge your mobile off it...as well as smoke lol. Sadly they don't do a version that will also weld, but give it time.

What did you start on?

[shokenore]

Oh nothing with any complicated curves or need for strength or water tightness or fit....
pictures to follow.


I have just done the radiator lower that I have now completed and is on the truck.