Making a GRP instrument pod

[rigpigpaul]

Hi all, I have an Instrument pod which is cracked at the edges. I have tried buying a new one but Goiot have stopped making them. I have been told that it will be difficult to repair it because it is plastic, not GRP. The pod is T shaped with three Raymarine instruments at the top and a Raymarine C70 chart plotter below. The plan is this winter to remove the pod cover and use it to make a GRP mould and then use the mould to make a new pod cover. The pod is white. I have no experience working with GRP. Is the job difficult and are there any major problems to consider. My one concern is achieving a smooth white surface/finish. Any tips greatly appreciated. RPP

 

[nimbusgb]

Nice radii on corners, good release agent. Look out for using an ABS pod as a mould because - 1 polyester resin will kill it and 2 injection moulded pods may have 'gotchas' in terms of reverse release angles that make getting the moulded article free from the mould impossible.

You need to work out how to mage a flange to divide the mould in two. Build a female mould and then lay up halves in it. Means doing the job twice.

 

[lenseman]

Hi all, I have an Instrument pod which is cracked at the edges. I have tried buying a new one but Goiot have stopped making them. I have been told that it will be difficult to repair it because it is plastic, not GRP. . . . . . Any tips greatly appreciated. RPP

Firstly, making a mound is very time consumng and not particularly easy PVA release coating etc etc. I speak from experience when I did what you are trying to do.

The plastic that has split, it 'might' be worth while checking to see if it softens and melts using the "Osma-weld" type glue. The type that glue-sniffers get high on? If you can obtain some, test an inside edge and see if it melts or softens. I doubt it but it is worth a try?

Secondly, and this is certainly a method I would try before attempting to make a GRP mound. A "Hot Glue Gun". Again on the inside and when it is nice and hot, try running the tip of the gun along the crack and fuse or weld the broken seam and flood it with hot glue?

Worth a try. There are other plastic experts on this forum who might come up with better ideas?



.

 

[chasroberts]

Fixed a bad crack on a corner of mine with the glue you use to weld/fix plastic drainpipes (PVC?) Anyway worked a treat and has held for three seasons now even though the pod is used constantly as a handhold whilst moving round the cockpit. Try everything you can before going down the make your own in GRP route. There lies many hours toil.....

Chas

 

[ukmctc]

Hi all, I have an Instrument pod which is cracked at the edges. I have tried buying a new one but Goiot have stopped making them. I have been told that it will be difficult to repair it because it is plastic, not GRP. The pod is T shaped with three Raymarine instruments at the top and a Raymarine C70 chart plotter below. The plan is this winter to remove the pod cover and use it to make a GRP mould and then use the mould to make a new pod cover. The pod is white. I have no experience working with GRP. Is the job difficult and are there any major problems to consider. My one concern is achieving a smooth white surface/finish. Any tips greatly appreciated. RPP

cheaper and easier to make a wooden one, or buy another make.

 

[Bobobolinsky]

If you have a grp boat, and no experience of grp, I would suggest that a pod would be an excellent way to learn in a small and controlled way.

A friend used to use epoxy as a first coat as it does not eat plastics. Another friend uses emulsion paint as a barrier coat, though it may not stick too well to your plastic, but it only needs to be a temporary barrier.

 

[rigpigpaul]

Thanks All for the advice. I will try the glue repair approach first. I will search the net for a white glue. RPP

 

[Bertramdriver]

If you have a grp boat, and no experience of grp, I would suggest that a pod would be an excellent way to learn in a small and controlled way.

A friend used to use epoxy as a first coat as it does not eat plastics. Another friend uses emulsion paint as a barrier coat, though it may not stick too well to your plastic, but it only needs to be a temporary barrier.

Good advice, cover the original with epoxy primer. Then make your female mould with polyurethane. Neither will kill the abs.
If you want good advice there are several good suppliers on eBay such as East coast fibreglass supplies who will spend the time explaining the processes.
It's not rocket science, it's not expensive and it is doable. I've just extended the width of my overhead console by 50% by slotting in precast 2mm grp sheeting with epoxy filler to get the shape right also I've just cast new logos for my boat using a silicon mould and two part polyeurathane. Bit of fun for the summer. After all if you have a grp boat and are living on a tight budget this is must know stuff.
Good luck