PU foam plug and body filler

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PU foam plug and body filler

Author	Message
TURK	TURK posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 101, Visits: 662	Thanks guys, efficient and rapid response time as usual I used that particular filler and hardener only recently .......... worked fine on the MDF. Seems a little odd to me that the very first skim of filler cured OK, then a couple more 'skims' ( build-up ) of filler, and things really went awry ! I had to place the plug in front of a radiator for three days for it to dry, but now it's began to crack ! Sanding was impossible, I tried 80grit sand paper but it was sticking to the filler and kind of creating 'balls' of filler .......... it felt as though I was trying to sand chewing gum. There was no sanding dust at all, it was simply accumulating into the sand paper. What's the 'bumper filler' you speak of Warren ? Basically what I'm trying to do is, to get these plugs to a very accurate dimension. If you were making these plugs yourself, would you cut and shape ( sand ) the plugs as near to the dimensions required, then apply Pattern-Coat Primer directly onto the PU foam ? TURK
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Warren (Staff)	Warren (Staff) posted 9 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 8.5K	I would agree that something has gone wrong. Even the bumper fillers can usually still be sanded. I would get it somewhere warm if you can. 30C plus for a good few hours might just be enough to push the cure the final bit. If not, you may be best using very coarse paper to grind it off then put on fresh. You could try overcoating with Pattern Coat Primer, however you would need to take extra care you don't sand much into the first layer of primer as you might easily break through to the bad filler. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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FLD	FLD posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 2.7K	Could the activator have gone off or be old? I've seen this with filler before but only when it's really old. More activator seems to cure the problem.
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TURK	TURK posted 9 Years Ago HOT Topic Details
Group: Forum Members Posts: 101, Visits: 662	Hi all, I'm in need of a little help guys ........ I watched ( and learned a great deal ) from Paul's 'Airbox' video on YouTube, I purchased and currently using the Low Density 48Kgs/m3 PU foam blocks, to get my 'form'. I then put a skim of body filler to harden the 'form' that will eventually be my plug for casting a resin mould. After the initial body filler 'skim' had hardened, I applied a few more layers of body filler to build-up the form to the dimensions I wanted. So basically, my plug now has about 3mm of body filler on it that needs to be sanded down smooth. Unfortunately, that isn't what happened ........... the body filler ( known as 'Bonda' ) turned out to be more like a rubbery texture !!! as we all probably know, it's impossible to sand down bubble gum ! Any of you know why it did this ? .......... did I overdo the 'skimming' of body filler ? The plugs have now been drying for four days, but the texture of the body filler is still quite soft, to the point where I can push my finger nail into it. This was the original 'skim' of body filler >> Then I applied a little more on to build it up as it were, so I could sand down the contours >> So, another question if I may ......... As I've never had any troubles with this sort of body filler, I use it all the time ( mostly on MDF plugs ) and never had any issues with it. D'you think there's been kind of a reaction with the PU foam ? should I have applied a few layers of Pattern-Coat Primer to the initial 'skim' of body filler ? or can I simply apply Pattern-Coat Primer directly onto the PU foam ? ( sorry, that's three questions ! ) There's loads more info in the following link, and the entire procedure here > PU foam plugs Many thanks for your time. TURK Tags moulds plugs PU foam quad headlight project T4 Edited 9 Years Ago by TURK
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