Bottom Paint for SIB for Extra Protection

jackreno · 08 November 2017, 21:41

Is there a brand of paint for a PVC boat that also offers it as a protection, I was talking with a guy that buys and fixes RIBs/SIBs and he said I would be better off painting the bottom of my new Bombard than adding another layer of material.

Is he right..

Lee1 · 08 November 2017, 21:59

I don't think any PVC paint is going to give any real protection, maybe something like the paint that use to be used on car underseals back in the day when they use to rust out and and need replacing, I think the same kind of paint is still used to paint the underside of 4x4's is kinda like liquid tar, (the old stuff back in the 1970-1980 was) I would go with a second layer of material and that's going to be costly and the amount of two part glue needed even more coastly. You could just glue a rubbing streak on down the centre and also strips each side of the bow and stern

If you want to use the paint idea Try some underseal auto paint on a piece of pvc to see if it sticks and if it melts the pvc before you put it on the boat

This is the auto underseal paint I'm thinking of and you would need a good few coats:

http://www.ironmongeryonline.com/ham...SABEgKX-fD_BwE

jackreno · 08 November 2017, 22:11

Lee1, is that stuff flexible, I used a similar product years ago in the back of a truck bed and it flake away over time.

I also forgot to mention the guy said to add many layers of rubber paint to make the coat thick than it will help protect the material underneath.

It would easier and cheaper this way but not sure it would offer more protection.

Lee1 · 08 November 2017, 22:18

I'm not sure it will stick to the PVC. . . Probably not, but it would stick to standard auto paint primer and if you clean and prime your PVC correctly before spraying on the paint primer the primer will stick to to PVC spray the primer on by only a very fine coats and only 2 coats.

Just spraying any normal paint on is not going to prevent any punctures or damage to the PVC

The underseal paint I remember was very thick like tar.

Mikefule · 09 November 2017, 05:22

Quote:

Originally Posted by jackreno

Is there a brand of paint for a PVC boat that also offers it as a protection, I was talking with a guy that buys and fixes RIBs/SIBs and he said I would be better off painting the bottom of my new Bombard than adding another layer of material.
Is he right..

This seems to be a solution in search of a problem, and not a very good solution.

If you paint the bottom of your SIB, the boat will be heavier, less flexible, harder to roll away, and will almost certainly have more drag in the water. You will have a less practical, less attractive boat and little, if any, additional protection against holes.

If you do nothing, but use the boat with reasonable care, the risk of holes is small, the boat won't sink if you get one, and they are relatively easy to repair.

John Kennett · 09 November 2017, 07:51

Quote:

Originally Posted by jackreno

he said I would be better off painting the bottom of my new Bombard than adding another layer of material.

Painting an inflatable is rarely a good idea. It's unlikely to be particularly successful, and won't achieve anything anyway apart from devaluing your boat. The only exception might be to squeeze a little bit more life out of a very tired old boat, but generally just don't do it.

Unless you have a particular overwhelming reason to, I wouldn't try to put another layer of fabric on it either. You'll just make the boat heavier and significantly more awkward to pack away. Any potential buyer in the future will question why you've done it, and quite likely walk away.

If it needs repairing then repair it, otherwise just get on and use it

jeffstevens763@g · 09 November 2017, 09:53

agree with the guys it will be a pig if you do paint or fabric the bottom with no benefit you will have problems if it gets punctured for repairs where as if it's original you can do a temp repair with tear aid and be on your way in a few minutes then permanent repair when you get home

jackreno · 09 November 2017, 16:22

Thanks for all the replies, yep just as I thought he was not giving me good info.

As to my use with the Bombard I am putting on a Jet outboard for shallow waters, so I am planning on adding some extra material for strength since the paint will not provide me extra protection

Duggy · 10 November 2017, 12:27

The Excel hire boats in St Ives harbour have an extra thick layer of textured rubber(?) glued to the bottom of them. Certainly seems to do the trick. I was talking to the lads operating them this summer and they certainly seem to be well able to stand the rigours of being constantly dragged on and off trailers and through the surf etc. I thought at the time it would be an idea to do something similar to my Honwave, which does seem quite prone to damage underneath.

John Kennett · 10 November 2017, 13:07

It sounds like these boats have unusually hard usage, and stay on trailers rather than being packed away after use. I can see that adding an extra layer of fabric might make sense in this situation, but this is a pretty specific niche and shouldn't be regarded as normal.

Highland Haggis · 10 November 2017, 13:37

I have on my excel vanguard 435 what a difference it makes will be doing it on my T40 as well worth the money

Lee1 · 10 November 2017, 20:24

Quote:

Originally Posted by Lee1

I don't think any PVC paint is going to give any real protection, maybe something like the paint that use to be used on car underseals back in the day when they use to rust out and and need replacing, I think the same kind of paint is still used to paint the underside of 4x4's is kinda like liquid tar, (the old stuff back in the 1970-1980 was) I would go with a second layer of material and that's going to be costly and the amount of two part glue needed even more coastly. You could just glue a rubbing streak on down the centre and also strips each side of the bow and stern

If you want to use the paint idea Try some underseal auto paint on a piece of pvc to see if it sticks and if it melts the pvc before you put it on the boat

This is the auto underseal paint I'm thinking of and you would need a good few coats:

Buy Hammerite Underbody Seal Tin 500ml online at £5.06 from Ironmongery Online.

I did state painting the boat bottom was not a good option and to fit underneath rubbing streaks!

Duggy · 12 November 2017, 08:54

Quote:

Originally Posted by John Kennett

It sounds like these boats have unusually hard usage, and stay on trailers rather than being packed away after use. I can see that adding an extra layer of fabric might make sense in this situation, but this is a pretty specific niche and shouldn't be regarded as normal.

No, you're right they do have very hard usage but I must say that I am seriously thinking of doing something similar to my T40 which I've already had to patch 3 times underneath, even though I try to treat it with kid gloves.