best way to prepare hypalon for lazy person

[BogMonster]

Like the title says

Everybody says it is important to get the surface right, I am thinking that a flap wheel on an electric drill will be a good solution to doing lots of this and much easier than elbow grease and sandpaper

something like: flap wheels

good idea or not?

any other effective low-effort ideas for surface prep of a largish area?

I have a dremel (sp?) mini-multi-widget-tool which has a little wire brush attachment but that is probably a bit too harsh....? I guess the last thing you want is something that might go through the rubbery bit into the stringy bit of the hypalon

[Stephen-RIB]

Flap sander is perfect, just be careful with them not to scuff through the fabric.

[jwalker]

I'm not negating what stephen-rib has said and for large areas such as a whole rubbing strake I would do the strake that way.
But, personally, I prefer to do the hypalon by hand and dip the abrasive paper into thinners or acetone (thiners being my choice, acetone evaporates too quickly). It swells and opens up the hypalon to improve the adhesion. It also makes the sanding easier. Don't finger it after sanding and the atmosphere must not be damp.

In poor conditions, it is possible to make what appear to be good joins but they fail after a period of time.

I prefer to use 3 layers of adhesive and if possible the first is left to dry completely.

Do a search here, it's been discussed many times.

[ribraff]

A Dremmel or Dye grinder works well with a rounded stone tip, you get a lot of control with this method and if careful can avoid oversanding, we use mini grinder disks for big areas but i would not recommend it to anyone first time.

[BogMonster]

I got the little Dremell (Draper actually, but the same sort of thing) multitool the other day and was faffing around with it on one of the offcuts I have that came with the boat. It was ok but would take forever to do the sort of area I am going to need to prepare for the reinforcing work on mine, never mind the fact I will be working upside down and my arms stop working after about 2 minutes in that position anyway! I did the 2 patches I fitted the other day by hand and working upside down on a deflated tube was very awkward so I think I will pump the tube up fairly firm and do the whole job like that, otherwise I can see ending up with 2 foot of wrinkled Hypalon bonded to itself, my face, my hair and my clothes in fact probably everything except the boat

Flap sander it is then, will go and buy a box of flap wheels on the weekend (I guess they will get bunged up fairly quickly with the rubbery stuff)

Thanks

[Biggles]

Steve,

I did a little piece on removing lots of old glue. Do a search under my name and look for the article under Old Glue Removal.

I'm not sure how to do the link, but its useful stuff.

Regards.

[gaviotapete]

hiya Stephen,
i just attached six handles to my hypalon avon and for the prep i used a random orbital sander with 80 grit sandpaper. it worked really well and went really fast. i used MEK afterward to clean it further. the sander is much easier to control (in my experience) than using flap wheels. fill up your tubes (if possible!) and sand away until your area looks uniformly clean and slightly abraded. wipe clean with solvent (MEK) and you should be ready to apply 2 part cement. i found using a small roller/caster works very well at applying lots of pressure to the joined materials. good luck!
G.pete

[BogMonster]

That is a good idea, hadn't thought of using an orbital sander, I have one at home

No problem with removing glue as there were no old patches on there before, but thanks for the tip anyway!

[jyasaki]

Personally, (if I was going to use a power sander at all) I would go over the area afterward (lightly) with a sanding screen (pierced metal sanding sheet - used a lot for rough wood sanding.) This will score the outer hypalon to a much greater degree, making the bond that much stronger.

Be really careful if you use MEK or toluene to soften the material first. The solvent melts the hypalon, making it really easy to sand too deep. I prefer to sand first, then just wipe off the loose bits with a solvent-wetted rag.

Don't forget to scuff up the patch, as well.

jky

[BogMonster]

Here it is

Biggles' Old Glue Removal Tip

Something else for the shopping list when I am over in July

[paul tilley]

we use 40 or 80 grit flap wheels as well as 24grit 4inch discs in an angle grinder or 36grit and 80grit ata bands in a die grinder ,got to be careful when doing it though