Building a mold

[Mr.freeze]

Hey guy's, has anyone built a mold to lay up their own fiberglass hull? I'm planning on making a mold of my 60" woody build to lay one up in fiberglass. Should I just wax the $#@% out of it and lay resin and cloth? or should I try to find mold release? I've never done it before so this should be fun. Anyway just looking for some pointers to save some time and money.

 

[Mr.freeze]

I haven't figured out how to link to my gallery but there are pics in there of the boats I'm redoing.

 

[Tom Foley]

I haven't figured out how to link to my gallery but there are pics in there of the boats I'm redoing.

If you just wax it ..it will stick and turn into a disaster !!!!!!!!!!!!!! Get some PVA from a fiberglass supply house like Fiberglass Coatings in St Pete Fl .this water soluble release coating will allow you to easily pull a mold off of your boat . However the edges will not be as sharp as the plug , in this case your boat , due to the thickness of the pva . Try it , you have nothing to lose !!

 

[eddieh]

I'm planning on making a mold of my 60" woody

Hell I'd call ripleys believe it or not they might make a mold of your 60" woody for ya.....

sorry man couldn't help it..

 

[Mark Poole ModVP]

I would not use PVA as a stand alone mold release. Without any other kind of release agent under it, one missed spot or tear in the PVA and you got a stuck mold. The multi coat paste wax method is time consuming but never fails but you must use mold release paste wax not just floor type wax. We just built a fishing boat and used PVA to make the first hull and I did not like the results. Nothing hurt, but lots of buffing to remove the grain left by the PVA.

 

[HTV Boats]

Mark is correct on using PVA over a waxed surface. Buff and wash with detergent before you wax and do 3-4 coats to make sure you cover every square inch. I have applied PVA with soft cotton (t-shirt) cloth to get a smooth finish and or have used a spray gun or air brush to spray on a thin coat of PVA. (poly vinyl alcohol) Cleans up with water very easily.

You should use a tooling gel coat to get the hardest first coat on the mold. Cure for a day and skin coat fiberglass over the gel-coat first, let cure, and look for any air voids which you can cut open and fill before you lay up the mold. Once made you can wet sand any imperfections in the mold with 600-1000 then buff and polish. Repeat clean and wax and PVA on your first parts. Once your confident wax only will release make a part. If your going to paint anyway just stay with PVA finish

 

[Joe_Knesek]

You might get something out of this.

http://video.google.com/videoplay?docid=8801536764731290932

 

[DENNY]

You might get something out of this.
http://video.google.com/videoplay?docid=8801536764731290932

THERE IS MORE TO IT THAN JUST THE PVA . USE fIBERGLASS "NO WAX GELCOAT RESIN FOR THE FIRST COAT (THICK). IF YOU WANT TO COLAR IT MAKE SURE YOU USE A "NUTRAL" TYPE . (WHITE GELL COAT WILL NOT TAKE THE COLAR CORRECTLY) WAIT 24 HRS FOR THE FRIST COAT TO DRY (THE LAMINATINING RESIN SOME TIMES WRICKELS IF YOU DON'T)

THE NEXT COAT USE "LAMINATING RESIN FOR ONE COAT WITH NO GLASS MAT.

AFTER THAT ADD THE MAT WITH THE LAMINATIING RESIN TILL YOU GET THE THICKNESS.

YOUR PLUG SHAPE IS VERY CRITICAL IT CAN'T HAVE ANY REVERSE ANGLES AND STRIGHT VERTICALS SHOULD BE LIMITED.

I GET MY SUPPIES FROM MERTON FIBERGLASS IN MASS. HE HAS A WEB SITE. AND WILL SHIP UPS IN QT TO GAL SIZES.

I USE "CHOPPED MAT" FOR MY THICK MOLDS AND "WOVEN MAT" FOR MY HULLS, USE THIN WOVEN AND LAMINATING RESIN TO ATTACH THE RAILS AND TRANSIT

KEEP THE RESINS IN A REFRIG. TO LENGTHIN THE SHELF LIFE. BRING TO ROOM TEMP BEFORE USING .

CALL ME IF YOU NEED MORE HELP 770 557 0447

 

[Ed.R]

You might get something out of this.
<a href="http://video.google.com/videoplay?docid=8801536764731290932" target="_blank">http://video.google.com/videoplay?docid=8801536764731290932</a>

KEEP THE RESINS IN A REFRIG. TO LENGTHIN THE SHELF LIFE. BRING TO ROOM TEMP BEFORE USING .

So I should bring all my West system and System 3 epoxies back outside in the cold instead of having them in a warmer enviroment?

Ed

 

[jydracing]

Hi Mr Freeze There are many ways to do molds and everyone use diffrent things. they can be built so that the part that comes out is a finished part ready for use. Or the part will need to be sanded and painted. If you want sharp edges on the running surface for handling and speed DO NOT USE WAX AND PVA! there are better options out there. I use a release that leaves no build up and leaves all the sharp edges and angles the same. There are no wax or pva allowed in my shop. i can pull 21 hulls befroe reappling the release. If you want give me a call at 864-907-1006 and i will help all i can. See ya Jimmy

 

[Jim Caldwell]

Freecote 770 MC ????