fibre glass help

[steveo3002]

im trying to do a little diy project , ive made a mold or buck or whatever you call it that im laying the matt and resin into

where i have sharp angles i stipple the matt down but its trying to straighten up again and wont stay around bends

how do i fibre glass around bends...lighter matt i guess?

 

[the snooper]

im trying to do a little diy project , ive made a mold or buck or whatever you call it that im laying the matt and resin into

where i have sharp angles i stipple the matt down but its trying to straighten up again and wont stay around bends

how do i fibre glass around bends...lighter matt i guess?

Are you putting enough resin on ?

 

[Parm]

You need to wet it more. with enough resin it should hold to the shape of your mould

 

[steveo3002]

was soaked

im talking about external corners

 

[Yamhon]

If you cherry pick through this playlist from the Sail Life channel on YouTube; you'll see loads of use of GRP, I'm sure you'll be able to pick up some tips from what Mads as done on his boat.

 

[Yamhon]

Think I may have shared wrong link; look for 'Project Athena'

 

[gaz1]

im trying to do a little diy project , ive made a mold or buck or whatever you call it that im laying the matt and resin into

where i have sharp angles i stipple the matt down but its trying to straighten up again and wont stay around bends

how do i fibre glass around bends...lighter matt i guess?

how thick is your matt that your using?

 

[Bullet2012]

Are your external sides large enough ?
Common practice is to oversize the external edges and then trim to size once released from the mould

 

[steveo3002]

how thick is your matt that your using?

i dont even know what spec it is...my guess is this is heavy stuff for big job and i needed tissue for small jobs

pulled it out the mold now....good enough for a newbie lol , will put a picture on later

whats the score with it staying sticky? will it dry off eventually

 

[Yamhon]

i dont even know what spec it is...my guess is this is heavy stuff for big job and i needed tissue for small jobs

pulled it out the mold now....good enough for a newbie lol , will put a picture on later

whats the score with it staying sticky? will it dry off eventually

From what I've seen on YouTube; might take 24-48 hours to fully cure.

 

[fixerupper]

I have always left it in the mould until it's hard , I would be concerned the shape would distort ...the speed of cure is down to the correct ratio of resin and hardener and the ambient temperature and humidity as far as I know ..

 

[steveo3002]

its rock hard...just makes your hands sticky handling it

 

[Parm]

I have always left it in the mould until it's hard , I would be concerned the shape would distort ...the speed of cure is down to the correct ratio of resin and hardener and the ambient temperature and humidity as far as I know ..

Spot on

 

[carbon]

How old is the resin and catalyst?

 

[steveo3002]

How old is the resin and catalyst?

its probably had a couple of birthdays now

 

[Burdekin]

Are you using polyester resin?

Is it cut strand Matt or woven roving?

 

[Keith 66]

The problem you describe with glass lifting off is caused by you not having a big enough radius on your plug or mould. Fibreglass does not like sharp corners either internal or external. Radius's are good! Dont matter how much resin you put on or how much you roll it it will lift off if the corner is too tight.
Glassing into an internal corner that is square will often result in a line of air bubbles along the sharp edge, this can be avoided before you lay the glass on by squoozing a fillet of gelcoat thickend by cotton fibres into the corner first.
I take it you are using a roller? The best type is a paddle wheel roller & it is used to consolidate the wet fibreglass & helps roll air bubbles out.
I used to build an 18ft fibreglass rowing dinghy, she was a lovely boat & fast but was simulated clinker the mould having originally been lifted from a clinker built wooden boat.
The overlapping plank edges or lands meant that to get a decent quality moulding all had to be carefully radiused.
As there were 9 planks a side this meant approx 162ft run of gelcoat filler had to be applied. This increased the labour cost of laying up the hull by over 40%.
I sold that mold & built a smooth skinned rowing boat, she is far easier to lay up & lighter too!

 

[steveo3002]

Are you using polyester resin?

Is it cut strand Matt or woven roving?

polyester and cut strand

i think keith is on the money there...needs a radius , not too worry it came out okay for what i need

 

[The_Yellow_Ardvark]

im trying to do a little diy project , ive made a mold or buck or whatever you call it that im laying the matt and resin into

where i have sharp angles i stipple the matt down but its trying to straighten up again and wont stay around bends

how do i fibre glass around bends...lighter matt i guess?

On bends you need a radius, plus a finer matt.

When you have stippled it, try using a foam roller on the bends and edges.

I am no expert but have done a small bit of fibre glassing. Mosty car bumper repairs and a on one robin.

 

[The_Yellow_Ardvark]

I have always left it in the mould until it's hard , I would be concerned the shape would distort ...the speed of cure is down to the correct ratio of resin and hardener and the ambient temperature and humidity as far as I know ..

When I last brought some kit, the supplier handed me a chart on how long it would be best to leave the resin to cure.
Based on temp, humidity etc.