Blisters And Rust Bleeding

Blisters And Rust Bleeding

Hi Paul & Karen, sorry I haven't been able to get to this one before now. Typically with these sort of surface problems, they are difficult to be absolutely certain without seeing the hull in the flesh so to speak. I am fairly sure however that your problem is a plastering one. I suspect that there are voids running down from the deck edge area, and water is coming down and working from the inside to the out. This is often found in hulls which are 'two-shot', plastered and not enough care has been taken to complete the mateing. If this is the case.....then it is not too difficult to fix. You will probably find the water is getting in under the bulwarks/rubbing band or fixing bolt holes. You will have to remove the offending items, seal the deck edge and seal where the water is getting in. It is all very well a shipwright suggesting you dry out the area of the hull, but remember the hull is not porous, if it is, it's because it's got voids carrying water through them. Drying from the outside will only help with the final filling process if the void carrying the water has already been sealed. Regards

Colin Brookes...colb@xtra.co.nz

P.S Since writing this to the forum we have been doing some talking to shipwrights and have been told that the best way to fix her is to grind back the blisters and all the epoxy around them, thus exposing the ferro, Then using a heat gun begin the process of drying out the hull in these regions...?? (not sure if this is good for the hull???) hope you can assist with any info, regards

Paul & Karen

Hi, Well as the owners of a 49' North American Auxillary Ketch (launched 1986, builder: Graham Parker of Geelong, Victoria). Her topsides require regular cleaning of rust bleeds through her epoxy faired sheath.(Hemple's Rust Cleaner)I have tried drilling each of the bleed points, daubed "Rust Converter" at the base of the drilling and then filled with Expoy. This has slowed down the rate of bleed but in some regards the new bleed has established at the bonding of the epoxy plug. any suggestions on how what is causing the bleeding etc and how to cure it permantly. The second problem is blistering of the hull about 100mm down from the bulwark. What may be causing this and how should it be cured? We have learned alot from our ferro hulled boat.. and are keen to have her looking her best at all times.. love fooling the boat agents who think she is either timber or steel.. and cant wait to have the GRP boys.. droolling over her bright shiny hull.. hope you can help

Paul & Karen - Sydney....cato@ans.com.au

Want to know more about Ferrocement?

The information and comments given on this 'World Of Ferroboats', website are based on first-hand experience gained by the contributors over many years of use, designing, surveying, building and repairing ferro-cement boats.