P38 Filler under top side paint.

[Ceirwan]

I'm repainting the decks, cockpit and general top sides of the boat. (not the Hull though) and there are a few places that need minor fairing. (rope abrasion marks etc)
The plan is to use toplac, would I be ok to use the p38 fairing filler that you can get at most car places for this job as it will be sealed underneath the paint anyway, or is it not really suitable?

The marine fillers I've tried so far all have a much harder consistency to work with.

 

[TQA]

I use West System with their light weight fairing microballons. Sands easily and feather edges well.

People do use P38 but it is hydroscopic and if it can find moisture you will get blisters appearing.

1/2p of tar IMHO.

 

[Ceirwan]

I have some West System but I invariably find when I mix it I make an incredible mess and struggle to mix it in properly, that and the fact the pumps clog up. But if its likely to blister I'll avoid the P38.

 

[Ardenfour]

I've used P38 type filler several times in the past, toplac and brightside, never had a problem

 

[Tranona]

You might find International Watertite better, although much more expensive than P38 it is epoxy and you can get it in either small tubes or bigger tins depending on how much you have to do. Sands easily to good base for paint. However, if you have epoxy already mixing your own with fairing filler is easy. would not bother with pumps as the amount you need is small and the mix is not so critical as it is not structural. Never had a problem getting the right consistency with fairing filler, and it is the right stuff for this type of job.

 

[Javelin]

We use Nautix Blue epoxy filler - 50/50 mix - easy to sand and the consistency makes it so easy to use.

 

[ghostlymoron]

People always recommend West system stuff, however, you can spend a small fortune on epoxy, micro balloons and dispensers to sit on the shelf for ages when what you really need is a ready mixed filler with a good shelf life.

I use West System with their light weight fairing microballons. Sands easily and feather edges well.

People do use P38 but it is hydroscopic and if it can find moisture you will get blisters appearing.

1/2p of tar IMHO.

 

[TQA]

People always recommend West system stuff, however, you can spend a small fortune on epoxy, micro balloons and dispensers to sit on the shelf for ages when what you really need is a ready mixed filler with a good shelf life.

I take your point and yes West system is more expensive that some other epoxies. My West resin and filler is at least 8 years old [ came with the boat]. I replaced the hardener 2 years ago as it had gone black. Test batches still cured hard but ??

West is sensitive to the ratio so I use syringes to measure small quantities. Mixing large batches of epoxy in the the Caribbean temps is a BAD idea even with super slow.

I have seen a faired hull develop saucer size blisters and someone else scraping a load of fairing off after deciding that it was never going to cure Neither were West.

If you have a problem you can go to West and they are helpful. Where do start looking for help if you are using the stuff that comes in recycled rum bottles or is bought from the auto shop

 

[ccscott49]

I use west or SP epoxy with 410 ultrafine filler, works great and sands easily, I wont use car body filler anywhere on the boat, its the wrong stuff and that's that.